diff --git a/README.md b/README.md
index ea70317..a9d91bb 100644
--- a/README.md
+++ b/README.md
@@ -80,3 +80,17 @@ ensure that all tests pass by running the following from the project root:
 
 The use of gocheck is summarily being phased out; however, old tests that use it
 still exist.
+
+# Contributing
+
+Same as for the `prometheus/prometheus` repository, we are using
+Gerrit to manage reviews of pull-requests for this repository. See
+[`CONTRIBUTING.md`](https://github.com/prometheus/prometheus/blob/master/CONTRIBUTING.md)
+in the `prometheus/prometheus` repository for details (but replace the
+`prometheus` repository name by `client_golang`).
+
+Please try to avoid warnings flagged by [`go
+vet`](https://godoc.org/code.google.com/p/go.tools/cmd/vet) and by
+[`golint`](https://github.com/golang/lint), and pay attention to the
+[Go Code Review
+Comments](https://code.google.com/p/go-wiki/wiki/CodeReviewComments).
diff --git a/extraction/discriminator.go b/extraction/discriminator.go
index f0356f8..8d6b4a4 100644
--- a/extraction/discriminator.go
+++ b/extraction/discriminator.go
@@ -14,6 +14,7 @@
 package extraction
 
 import (
+	"errors"
 	"fmt"
 	"mime"
 	"net/http"
@@ -24,20 +25,20 @@ import (
 // Processor can be found, an error is returned.
 func ProcessorForRequestHeader(header http.Header) (Processor, error) {
 	if header == nil {
-		return nil, fmt.Errorf("Received illegal and nil header.")
+		return nil, errors.New("received illegal and nil header")
 	}
 
 	mediatype, params, err := mime.ParseMediaType(header.Get("Content-Type"))
 	if err != nil {
-		return nil, fmt.Errorf("Invalid Content-Type header %q: %s", header.Get("Content-Type"), err)
+		return nil, fmt.Errorf("invalid Content-Type header %q: %s", header.Get("Content-Type"), err)
 	}
 	switch mediatype {
 	case "application/vnd.google.protobuf":
 		if params["proto"] != "io.prometheus.client.MetricFamily" {
-			return nil, fmt.Errorf("Unrecognized Protocol Message %s", params["proto"])
+			return nil, fmt.Errorf("unrecognized protocol message %s", params["proto"])
 		}
 		if params["encoding"] != "delimited" {
-			return nil, fmt.Errorf("Unsupported Encoding %s", params["encoding"])
+			return nil, fmt.Errorf("unsupported encoding %s", params["encoding"])
 		}
 		return MetricFamilyProcessor, nil
 	case "text/plain":
@@ -48,26 +49,26 @@ func ProcessorForRequestHeader(header http.Header) (Processor, error) {
 			// Fallback: most recent version.
 			return Processor004, nil
 		default:
-			return nil, fmt.Errorf("Unrecognized API version %s", params["version"])
+			return nil, fmt.Errorf("unrecognized API version %s", params["version"])
 		}
 	case "application/json":
-		var prometheusApiVersion string
+		var prometheusAPIVersion string
 
 		if params["schema"] == "prometheus/telemetry" && params["version"] != "" {
-			prometheusApiVersion = params["version"]
+			prometheusAPIVersion = params["version"]
 		} else {
-			prometheusApiVersion = header.Get("X-Prometheus-API-Version")
+			prometheusAPIVersion = header.Get("X-Prometheus-API-Version")
 		}
 
-		switch prometheusApiVersion {
+		switch prometheusAPIVersion {
 		case "0.0.2":
 			return Processor002, nil
 		case "0.0.1":
 			return Processor001, nil
 		default:
-			return nil, fmt.Errorf("Unrecognized API version %s", prometheusApiVersion)
+			return nil, fmt.Errorf("unrecognized API version %s", prometheusAPIVersion)
 		}
 	default:
-		return nil, fmt.Errorf("Unsupported media type %q, expected %q", mediatype, "application/json")
+		return nil, fmt.Errorf("unsupported media type %q, expected %q", mediatype, "application/json")
 	}
 }
diff --git a/extraction/discriminator_test.go b/extraction/discriminator_test.go
index 5c11eef..85f43e9 100644
--- a/extraction/discriminator_test.go
+++ b/extraction/discriminator_test.go
@@ -14,14 +14,14 @@
 package extraction
 
 import (
-	"fmt"
+	"errors"
 	"net/http"
 	"testing"
 
 	"github.com/prometheus/client_golang/test"
 )
 
-func testDiscriminatorHttpHeader(t test.Tester) {
+func testDiscriminatorHTTPHeader(t test.Tester) {
 	var scenarios = []struct {
 		input  map[string]string
 		output Processor
@@ -29,12 +29,12 @@ func testDiscriminatorHttpHeader(t test.Tester) {
 	}{
 		{
 			output: nil,
-			err:    fmt.Errorf("Received illegal and nil header."),
+			err:    errors.New("received illegal and nil header"),
 		},
 		{
 			input:  map[string]string{"Content-Type": "application/json", "X-Prometheus-API-Version": "0.0.0"},
 			output: nil,
-			err:    fmt.Errorf("Unrecognized API version 0.0.0"),
+			err:    errors.New("unrecognized API version 0.0.0"),
 		},
 		{
 			input:  map[string]string{"Content-Type": "application/json", "X-Prometheus-API-Version": "0.0.1"},
@@ -44,7 +44,7 @@ func testDiscriminatorHttpHeader(t test.Tester) {
 		{
 			input:  map[string]string{"Content-Type": `application/json; schema="prometheus/telemetry"; version=0.0.0`},
 			output: nil,
-			err:    fmt.Errorf("Unrecognized API version 0.0.0"),
+			err:    errors.New("unrecognized API version 0.0.0"),
 		},
 		{
 			input:  map[string]string{"Content-Type": `application/json; schema="prometheus/telemetry"; version=0.0.1`},
@@ -64,12 +64,12 @@ func testDiscriminatorHttpHeader(t test.Tester) {
 		{
 			input:  map[string]string{"Content-Type": `application/vnd.google.protobuf; proto="illegal"; encoding="delimited"`},
 			output: nil,
-			err:    fmt.Errorf("Unrecognized Protocol Message illegal"),
+			err:    errors.New("unrecognized protocol message illegal"),
 		},
 		{
 			input:  map[string]string{"Content-Type": `application/vnd.google.protobuf; proto="io.prometheus.client.MetricFamily"; encoding="illegal"`},
 			output: nil,
-			err:    fmt.Errorf("Unsupported Encoding illegal"),
+			err:    errors.New("unsupported encoding illegal"),
 		},
 		{
 			input:  map[string]string{"Content-Type": `text/plain; version=0.0.4`},
@@ -84,7 +84,7 @@ func testDiscriminatorHttpHeader(t test.Tester) {
 		{
 			input:  map[string]string{"Content-Type": `text/plain; version=0.0.3`},
 			output: nil,
-			err:    fmt.Errorf("Unrecognized API version 0.0.3"),
+			err:    errors.New("unrecognized API version 0.0.3"),
 		},
 	}
 
@@ -117,12 +117,12 @@ func testDiscriminatorHttpHeader(t test.Tester) {
 	}
 }
 
-func TestDiscriminatorHttpHeader(t *testing.T) {
-	testDiscriminatorHttpHeader(t)
+func TestDiscriminatorHTTPHeader(t *testing.T) {
+	testDiscriminatorHTTPHeader(t)
 }
 
-func BenchmarkDiscriminatorHttpHeader(b *testing.B) {
+func BenchmarkDiscriminatorHTTPHeader(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		testDiscriminatorHttpHeader(b)
+		testDiscriminatorHTTPHeader(b)
 	}
 }
diff --git a/extraction/processor0_0_1.go b/extraction/processor0_0_1.go
index 50d4cf4..6c9760d 100644
--- a/extraction/processor0_0_1.go
+++ b/extraction/processor0_0_1.go
@@ -35,9 +35,9 @@ const (
 	percentile001 = "percentile"
 )
 
-// Processor002 is responsible for decoding payloads from protocol version
+// Processor001 is responsible for decoding payloads from protocol version
 // 0.0.1.
-var Processor001 Processor = &processor001{}
+var Processor001 = &processor001{}
 
 // processor001 is responsible for handling API version 0.0.1.
 type processor001 struct{}
@@ -77,7 +77,7 @@ func (p *processor001) ProcessSingle(in io.Reader, out Ingester, o *ProcessOptio
 			case gauge001, counter001:
 				sampleValue, ok := value.Value.(float64)
 				if !ok {
-					err = fmt.Errorf("Could not convert value from %s %s to float64.", entity, value)
+					err = fmt.Errorf("could not convert value from %s %s to float64", entity, value)
 					if err := out.Ingest(&Result{Err: err}); err != nil {
 						return err
 					}
@@ -95,7 +95,7 @@ func (p *processor001) ProcessSingle(in io.Reader, out Ingester, o *ProcessOptio
 			case histogram001:
 				sampleValue, ok := value.Value.(map[string]interface{})
 				if !ok {
-					err = fmt.Errorf("Could not convert value from %q to a map[string]interface{}.", value.Value)
+					err = fmt.Errorf("could not convert value from %q to a map[string]interface{}", value.Value)
 					if err := out.Ingest(&Result{Err: err}); err != nil {
 						return err
 					}
@@ -105,7 +105,7 @@ func (p *processor001) ProcessSingle(in io.Reader, out Ingester, o *ProcessOptio
 				for percentile, percentileValue := range sampleValue {
 					individualValue, ok := percentileValue.(float64)
 					if !ok {
-						err = fmt.Errorf("Could not convert value from %q to a float64.", percentileValue)
+						err = fmt.Errorf("could not convert value from %q to a float64", percentileValue)
 						if err := out.Ingest(&Result{Err: err}); err != nil {
 							return err
 						}
diff --git a/extraction/processor0_0_1_test.go b/extraction/processor0_0_1_test.go
index 1df5706..9142d60 100644
--- a/extraction/processor0_0_1_test.go
+++ b/extraction/processor0_0_1_test.go
@@ -14,7 +14,7 @@
 package extraction
 
 import (
-	"fmt"
+	"errors"
 	"os"
 	"path"
 	"sort"
@@ -68,7 +68,7 @@ func testProcessor001Process(t test.Tester) {
 	var scenarios = []testProcessor001ProcessScenario{
 		{
 			in:  "empty.json",
-			err: fmt.Errorf("unexpected end of JSON input"),
+			err: errors.New("unexpected end of JSON input"),
 		},
 		{
 			in: "test0_0_1-0_0_2.json",
diff --git a/extraction/processor0_0_2.go b/extraction/processor0_0_2.go
index 14a3e5a..fbf660e 100644
--- a/extraction/processor0_0_2.go
+++ b/extraction/processor0_0_2.go
@@ -23,7 +23,7 @@ import (
 
 // Processor002 is responsible for decoding payloads from protocol version
 // 0.0.2.
-var Processor002 = new(processor002)
+var Processor002 = &processor002{}
 
 type histogram002 struct {
 	Labels map[string]string            `json:"labels"`
@@ -60,7 +60,7 @@ func (p *processor002) ProcessSingle(in io.Reader, out Ingester, o *ProcessOptio
 			var values []counter002
 
 			if err := json.Unmarshal(entity.Metric.Values, &values); err != nil {
-				err := fmt.Errorf("Could not extract %s value: %s", entity.Metric.Type, err)
+				err := fmt.Errorf("could not extract %s value: %s", entity.Metric.Type, err)
 				if err := out.Ingest(&Result{Err: err}); err != nil {
 					return err
 				}
@@ -81,7 +81,7 @@ func (p *processor002) ProcessSingle(in io.Reader, out Ingester, o *ProcessOptio
 			var values []histogram002
 
 			if err := json.Unmarshal(entity.Metric.Values, &values); err != nil {
-				err := fmt.Errorf("Could not extract %s value: %s", entity.Metric.Type, err)
+				err := fmt.Errorf("could not extract %s value: %s", entity.Metric.Type, err)
 				if err := out.Ingest(&Result{Err: err}); err != nil {
 					return err
 				}
@@ -102,7 +102,7 @@ func (p *processor002) ProcessSingle(in io.Reader, out Ingester, o *ProcessOptio
 			}
 
 		default:
-			err := fmt.Errorf("Unknown metric type %q", entity.Metric.Type)
+			err := fmt.Errorf("unknown metric type %q", entity.Metric.Type)
 			if err := out.Ingest(&Result{Err: err}); err != nil {
 				return err
 			}
diff --git a/extraction/processor0_0_2_test.go b/extraction/processor0_0_2_test.go
index cededbf..a871cbc 100644
--- a/extraction/processor0_0_2_test.go
+++ b/extraction/processor0_0_2_test.go
@@ -14,7 +14,7 @@
 package extraction
 
 import (
-	"fmt"
+	"errors"
 	"os"
 	"path"
 	"runtime"
@@ -69,7 +69,7 @@ func testProcessor002Process(t test.Tester) {
 	var scenarios = []testProcessor002ProcessScenario{
 		{
 			in:  "empty.json",
-			err: fmt.Errorf("EOF"),
+			err: errors.New("EOF"),
 		},
 		{
 			in: "test0_0_1-0_0_2.json",
diff --git a/model/fingerprinting.go b/model/fingerprinting.go
index 5be5892..313ff30 100644
--- a/model/fingerprinting.go
+++ b/model/fingerprinting.go
@@ -36,6 +36,8 @@ func (f *Fingerprint) String() string {
 	return strings.Join([]string{fmt.Sprintf("%020d", f.Hash), f.FirstCharacterOfFirstLabelName, fmt.Sprint(f.LabelMatterLength), f.LastCharacterOfLastLabelValue}, "-")
 }
 
+// Less compares first the Hash, then the FirstCharacterOfFirstLabelName, then
+// the LabelMatterLength, then the LastCharacterOfLastLabelValue.
 func (f *Fingerprint) Less(o *Fingerprint) bool {
 	if f.Hash < o.Hash {
 		return true
@@ -67,6 +69,7 @@ func (f *Fingerprint) Less(o *Fingerprint) bool {
 	return false
 }
 
+// Equal uses the same semantics as Less.
 func (f *Fingerprint) Equal(o *Fingerprint) bool {
 	if f.Hash != o.Hash {
 		return false
@@ -146,8 +149,8 @@ func (f *Fingerprint) LoadFromMetric(m Metric) {
 	f.LastCharacterOfLastLabelValue = lastCharacterOfLastLabelValue
 }
 
-// Represents a collection of Fingerprint subject to a given natural sorting
-// scheme.
+// Fingerprints represents a collection of Fingerprint subject to a given
+// natural sorting scheme. It implements sort.Interface.
 type Fingerprints []*Fingerprint
 
 func (f Fingerprints) Len() int {
@@ -162,8 +165,10 @@ func (f Fingerprints) Swap(i, j int) {
 	f[i], f[j] = f[j], f[i]
 }
 
-type FingerprintSet map[Fingerprint]bool
+// FingerprintSet is a set of Fingerprints.
+type FingerprintSet map[Fingerprint]struct{}
 
+// Equal returns true if both sets contain the same elements (and not more).
 func (s FingerprintSet) Equal(o FingerprintSet) bool {
 	if len(s) != len(o) {
 		return false
@@ -178,6 +183,7 @@ func (s FingerprintSet) Equal(o FingerprintSet) bool {
 	return true
 }
 
+// Intersection returns the elements contained in both sets.
 func (s FingerprintSet) Intersection(o FingerprintSet) FingerprintSet {
 	myLength, otherLength := len(s), len(o)
 	if myLength == 0 || otherLength == 0 {
@@ -196,7 +202,7 @@ func (s FingerprintSet) Intersection(o FingerprintSet) FingerprintSet {
 
 	for k := range subSet {
 		if _, ok := superSet[k]; ok {
-			out[k] = true
+			out[k] = struct{}{}
 		}
 	}
 
diff --git a/model/labelname.go b/model/labelname.go
index 310bd72..6634662 100644
--- a/model/labelname.go
+++ b/model/labelname.go
@@ -18,18 +18,20 @@ import (
 )
 
 const (
-	// The label name prefix to prepend if a synthetic label is already present
-	// in the exported metrics.
+	// ExporterLabelPrefix is the label name prefix to prepend if a
+	// synthetic label is already present in the exported metrics.
 	ExporterLabelPrefix LabelName = "exporter_"
 
-	// The label name indicating the metric name of a timeseries.
+	// MetricNameLabel is the label name indicating the metric name of a
+	// timeseries.
 	MetricNameLabel LabelName = "__name__"
 
-	// ReservedLabelPrefix is a prefix which is not legal in user-supplied label
-	// names.
+	// ReservedLabelPrefix is a prefix which is not legal in user-supplied
+	// label names.
 	ReservedLabelPrefix = "__"
 
-	// The label name indicating the job from which a timeseries was scraped.
+	// JobLabel is the label name indicating the job from which a timeseries
+	// was scraped.
 	JobLabel LabelName = "job"
 )
 
@@ -37,6 +39,7 @@ const (
 // therewith.
 type LabelName string
 
+// LabelNames is a sortable LabelName slice. In implements sort.Interface.
 type LabelNames []LabelName
 
 func (l LabelNames) Len() int {
diff --git a/model/labelset.go b/model/labelset.go
index 539ecb8..04a6d8b 100644
--- a/model/labelset.go
+++ b/model/labelset.go
@@ -26,7 +26,7 @@ import (
 // match.
 type LabelSet map[LabelName]LabelValue
 
-// Helper function to non-destructively merge two label sets.
+// Merge is a helper function to non-destructively merge two label sets.
 func (l LabelSet) Merge(other LabelSet) LabelSet {
 	result := make(LabelSet, len(l))
 
@@ -56,6 +56,7 @@ func (l LabelSet) String() string {
 	}
 }
 
+// MergeFromMetric merges Metric into this LabelSet.
 func (l LabelSet) MergeFromMetric(m Metric) {
 	for k, v := range m {
 		l[k] = v
diff --git a/model/labelvalue.go b/model/labelvalue.go
index 6a197cd..69b5041 100644
--- a/model/labelvalue.go
+++ b/model/labelvalue.go
@@ -20,6 +20,7 @@ import (
 // A LabelValue is an associated value for a LabelName.
 type LabelValue string
 
+// LabelValues is a sortable LabelValue slice. It implements sort.Interface.
 type LabelValues []LabelValue
 
 func (l LabelValues) Len() int {
diff --git a/model/metric.go b/model/metric.go
index 0b7e04a..3379f95 100644
--- a/model/metric.go
+++ b/model/metric.go
@@ -23,6 +23,7 @@ import (
 // a singleton and refers to one and only one stream of samples.
 type Metric map[LabelName]LabelValue
 
+// Equal compares the fingerprints of both metrics.
 func (m Metric) Equal(o Metric) bool {
 	lFingerprint := &Fingerprint{}
 	rFingerprint := &Fingerprint{}
@@ -33,6 +34,7 @@ func (m Metric) Equal(o Metric) bool {
 	return lFingerprint.Equal(rFingerprint)
 }
 
+// Before compares the fingerprints of both metrics.
 func (m Metric) Before(o Metric) bool {
 	lFingerprint := &Fingerprint{}
 	rFingerprint := &Fingerprint{}
@@ -64,6 +66,8 @@ func (m Metric) String() string {
 	}
 }
 
+// MergeFromLabelSet merges a label set into this Metric, prefixing a collision
+// prefix to the label names merged from the label set where required.
 func (m Metric) MergeFromLabelSet(labels LabelSet, collisionPrefix LabelName) {
 	for k, v := range labels {
 		if collisionPrefix != "" {
diff --git a/model/sample.go b/model/sample.go
index 12d22ec..4b0eb07 100644
--- a/model/sample.go
+++ b/model/sample.go
@@ -13,12 +13,14 @@
 
 package model
 
+// Sample is a sample value with a timestamp and a metric.
 type Sample struct {
 	Metric    Metric
 	Value     SampleValue
 	Timestamp Timestamp
 }
 
+// Equal compares first the metrics, then the timestamp, then the value.
 func (s *Sample) Equal(o *Sample) bool {
 	if s == o {
 		return true
@@ -37,12 +39,14 @@ func (s *Sample) Equal(o *Sample) bool {
 	return true
 }
 
+// Samples is a sortable Sample slice. It implements sort.Interface.
 type Samples []*Sample
 
 func (s Samples) Len() int {
 	return len(s)
 }
 
+// Less compares first the metrics, then the timestamp.
 func (s Samples) Less(i, j int) bool {
 	switch {
 	case s[i].Metric.Before(s[j].Metric):
diff --git a/model/samplevalue.go b/model/samplevalue.go
index 2557fe5..72445cc 100644
--- a/model/samplevalue.go
+++ b/model/samplevalue.go
@@ -21,10 +21,12 @@ import (
 // time.
 type SampleValue float64
 
+// Equal does a straight v==o.
 func (v SampleValue) Equal(o SampleValue) bool {
 	return v == o
 }
 
+// MarshalJSON implements json.Marshaler.
 func (v SampleValue) MarshalJSON() ([]byte, error) {
 	return []byte(fmt.Sprintf(`"%f"`, v)), nil
 }
diff --git a/model/timestamp.go b/model/timestamp.go
index 1b8479f..a12478f 100644
--- a/model/timestamp.go
+++ b/model/timestamp.go
@@ -23,14 +23,15 @@ import (
 //               methods below, so it will be easy to change this later
 //               without requiring significant user code changes.
 
-// Time in seconds since the epoch (January 1, 1970 UTC).
+// Timestamp is the number of seconds since the epoch (1970-01-01 00:00 UTC)
+// without leap seconds.
 type Timestamp int64
 
 const (
-	// The minimum supported time resolution. This has to be at least
-	// native_time.Second in order for the code below to work.
+	// MinimumTick is the minimum supported time resolution. This has to be
+	// at least native_time.Second in order for the code below to work.
 	MinimumTick = native_time.Second
-	// The timestamp duration equivalent to one second.
+	// second is the timestamp duration equivalent to one second.
 	second = int64(native_time.Second / MinimumTick)
 )
 
@@ -44,7 +45,7 @@ func (t Timestamp) Before(o Timestamp) bool {
 	return t < o
 }
 
-// Before reports whether the timestamp t is after o.
+// After reports whether the timestamp t is after o.
 func (t Timestamp) After(o Timestamp) bool {
 	return t > o
 }
diff --git a/model/timestamp_test.go b/model/timestamp_test.go
index d2faf6e..12d97bd 100644
--- a/model/timestamp_test.go
+++ b/model/timestamp_test.go
@@ -72,12 +72,12 @@ func TestDuration(t *testing.T) {
 
 	ts := TimestampFromTime(goTime)
 	if !goTime.Add(duration).Equal(ts.Add(duration).Time()) {
-		t.Fatalf("%d. Expected %s to be equal to %s", goTime.Add(duration), ts.Add(duration))
+		t.Fatalf("Expected %s to be equal to %s", goTime.Add(duration), ts.Add(duration))
 	}
 
 	earlier := ts.Add(-duration)
 	delta := ts.Sub(earlier)
 	if delta != duration {
-		t.Fatalf("%d. Expected %s to be equal to %s", delta, duration)
+		t.Fatalf("Expected %s to be equal to %s", delta, duration)
 	}
 }
diff --git a/prometheus/constants.go b/prometheus/constants.go
index 6227553..385b467 100644
--- a/prometheus/constants.go
+++ b/prometheus/constants.go
@@ -8,30 +8,35 @@ package prometheus
 
 var (
 	// NilLabels is a nil set of labels merely for end-user convenience.
-	NilLabels map[string]string = nil
+	NilLabels map[string]string
 
-	// The default http.Handler for exposing telemetric data over a web services
-	// interface.
+	// DefaultHandler is the default http.Handler for exposing telemetric
+	// data over a web services interface.
 	DefaultHandler = DefaultRegistry.Handler()
 
-	// This is the default registry with which Metric objects are associated.
+	// DefaultRegistry with which Metric objects are associated.
 	DefaultRegistry = NewRegistry()
 )
 
 const (
-	// A prefix to be used to namespace instrumentation flags from others.
+	// FlagNamespace is a prefix to be used to namespace instrumentation
+	// flags from others.
 	FlagNamespace = "telemetry."
 
-	// The format of the exported data.  This will match this library's version,
-	// which subscribes to the Semantic Versioning scheme.
+	// APIVersion is the version of the format of the exported data.  This
+	// will match this library's version, which subscribes to the Semantic
+	// Versioning scheme.
 	APIVersion = "0.0.2"
 
-	// The content type and schema information set on telemetry data responses.
+	// TelemetryContentType is the content type and schema information set
+	// on telemetry data responses.
 	TelemetryContentType = `application/json; schema="prometheus/telemetry"; version=` + APIVersion
-	// The content type and schema information set on telemetry data responses.
+	// DelimitedTelemetryContentType is the content type and schema
+	// information set on telemetry data responses.
 	DelimitedTelemetryContentType = `application/vnd.google.protobuf; proto="io.prometheus.client.MetricFamily"; encoding="delimited"`
 
-	// The customary web services endpoint on which telemetric data is exposed.
+	// ExpositionResource is the customary web services endpoint on which
+	// telemetric data is exposed.
 	ExpositionResource = "/metrics"
 
 	baseLabelsKey = "baseLabels"
diff --git a/prometheus/helpers_test.go b/prometheus/helpers_test.go
index 39d7d63..f81dedd 100644
--- a/prometheus/helpers_test.go
+++ b/prometheus/helpers_test.go
@@ -7,9 +7,10 @@
 package prometheus
 
 import (
-	. "github.com/matttproud/gocheck"
 	"math"
 	"reflect"
+
+	. "github.com/matttproud/gocheck"
 )
 
 type isNaNChecker struct {
@@ -18,7 +19,7 @@ type isNaNChecker struct {
 
 // This piece provides a simple tester for the gocheck testing library to
 // ascertain if a value is not-a-number.
-var IsNaN Checker = &isNaNChecker{
+var IsNaN = &isNaNChecker{
 	&CheckerInfo{Name: "IsNaN", Params: []string{"value"}},
 }
 
@@ -43,7 +44,7 @@ type valueEqualsChecker struct {
 	*CheckerInfo
 }
 
-var ValueEquals Checker = &valueEqualsChecker{
+var ValueEquals = &valueEqualsChecker{
 	&CheckerInfo{Name: "IsValue", Params: []string{"obtained", "expected"}},
 }
 
diff --git a/prometheus/registry.go b/prometheus/registry.go
index d6359b5..31b06f8 100644
--- a/prometheus/registry.go
+++ b/prometheus/registry.go
@@ -98,15 +98,15 @@ type Registry interface {
 	YieldExporter() http.HandlerFunc
 }
 
-// This builds a new metric registry.  It is not needed in the majority of
-// cases.
+// NewRegistry builds a new metric registry.  It is not needed in the majority
+// of cases.
 func NewRegistry() Registry {
 	return &registry{
 		signatureContainers: make(map[uint64]*container),
 	}
 }
 
-// Associate a Metric with the DefaultRegistry.
+// Register associates a Metric with the DefaultRegistry.
 func Register(name, docstring string, baseLabels map[string]string, metric Metric) error {
 	return DefaultRegistry.Register(name, docstring, baseLabels, metric)
 }
@@ -116,7 +116,7 @@ func (r *registry) SetMetricFamilyInjectionHook(hook func() []*dto.MetricFamily)
 	r.metricFamilyInjectionHook = hook
 }
 
-// Implements json.Marshaler
+// MarshalJSON implements json.Marshaler.
 func (r *registry) MarshalJSON() ([]byte, error) {
 	containers := make(containers, 0, len(r.signatureContainers))
 
@@ -218,12 +218,12 @@ func (r *registry) Register(name, docstring string, baseLabels map[string]string
 
 // YieldBasicAuthExporter creates a http.HandlerFunc that is protected by HTTP's
 // basic authentication.
-func (register *registry) YieldBasicAuthExporter(username, password string) http.HandlerFunc {
+func (r *registry) YieldBasicAuthExporter(username, password string) http.HandlerFunc {
 	// XXX: Work with Daniel to get this removed from the library, as it is really
 	//      superfluous and can be much more elegantly accomplished via
 	//      delegation.
 	log.Println("Registry.YieldBasicAuthExporter is deprecated.")
-	exporter := register.YieldExporter()
+	exporter := r.YieldExporter()
 
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		authenticated := false
@@ -261,10 +261,10 @@ func decorateWriter(request *http.Request, writer http.ResponseWriter) io.Writer
 	return gziper
 }
 
-func (registry *registry) YieldExporter() http.HandlerFunc {
+func (r *registry) YieldExporter() http.HandlerFunc {
 	log.Println("Registry.YieldExporter is deprecated in favor of Registry.Handler.")
 
-	return registry.Handler()
+	return r.Handler()
 }
 
 func (r *registry) dumpDelimitedPB(w io.Writer) {
@@ -311,20 +311,20 @@ func (r *registry) dumpDelimitedExternalPB(w io.Writer) {
 	}
 }
 
-func (registry *registry) Handler() http.HandlerFunc {
-	return func(w http.ResponseWriter, r *http.Request) {
+func (r *registry) Handler() http.HandlerFunc {
+	return func(w http.ResponseWriter, req *http.Request) {
 		defer requestLatencyAccumulator(time.Now())
 
 		requestCount.Increment(nil)
 		header := w.Header()
 
-		writer := decorateWriter(r, w)
+		writer := decorateWriter(req, w)
 
 		if closer, ok := writer.(io.Closer); ok {
 			defer closer.Close()
 		}
 
-		accepts := goautoneg.ParseAccept(r.Header.Get("Accept"))
+		accepts := goautoneg.ParseAccept(req.Header.Get("Accept"))
 		for _, accept := range accepts {
 			if accept.Type != "application" {
 				continue
@@ -339,14 +339,14 @@ func (registry *registry) Handler() http.HandlerFunc {
 				}
 
 				header.Set(contentTypeHeader, DelimitedTelemetryContentType)
-				registry.dumpDelimitedPB(writer)
-				registry.dumpDelimitedExternalPB(writer)
+				r.dumpDelimitedPB(writer)
+				r.dumpDelimitedExternalPB(writer)
 				return
 			}
 		}
 
 		header.Set(contentTypeHeader, TelemetryContentType)
-		json.NewEncoder(writer).Encode(registry)
+		json.NewEncoder(writer).Encode(r)
 	}
 }