diff --git a/archiver.go b/archiver.go
index 31d4966aa..ca8542b65 100644
--- a/archiver.go
+++ b/archiver.go
@@ -530,7 +530,8 @@ func (j archiveJob) Copy() pipe.Job {
 }
 
 // Snapshot creates a snapshot of the given paths. If parentID is set, this is
-// used to compare the files with.
+// used to compare the files to the ones archived at the time this snapshot was
+// taken.
 func (arch *Archiver) Snapshot(p *Progress, paths []string, parentID backend.ID) (*Snapshot, backend.ID, error) {
 	debug.Log("Archiver.Snapshot", "start for %v", paths)
 
diff --git a/cache.go b/cache.go
index fb02024b3..24f7a17fd 100644
--- a/cache.go
+++ b/cache.go
@@ -13,7 +13,7 @@ import (
 	"github.com/restic/restic/server"
 )
 
-// Cache is used to handle the local cache.
+// Cache is used to locally cache items from a server.
 type Cache struct {
 	base string
 }
@@ -53,7 +53,9 @@ func (c *Cache) Has(t backend.Type, subtype string, id backend.ID) (bool, error)
 	return true, nil
 }
 
-// Store returns an io.WriteCloser that is used to save new information to.
+// Store returns an io.WriteCloser that is used to save new information to the
+// cache. The returned io.WriteCloser must be closed by the caller after all
+// data has been written.
 func (c *Cache) Store(t backend.Type, subtype string, id backend.ID) (io.WriteCloser, error) {
 	filename, err := c.filename(t, subtype, id)
 	if err != nil {
@@ -76,7 +78,8 @@ func (c *Cache) Store(t backend.Type, subtype string, id backend.ID) (io.WriteCl
 	return file, nil
 }
 
-// Load returns information from the cache.
+// Load returns information from the cache. The returned io.ReadCloser must be
+// closed by the caller.
 func (c *Cache) Load(t backend.Type, subtype string, id backend.ID) (io.ReadCloser, error) {
 	filename, err := c.filename(t, subtype, id)
 	if err != nil {
diff --git a/chunker/chunker.go b/chunker/chunker.go
index 9d19a2e2a..9e016e4dd 100644
--- a/chunker/chunker.go
+++ b/chunker/chunker.go
@@ -53,7 +53,7 @@ func (c Chunk) Reader(r io.ReaderAt) io.Reader {
 	return io.NewSectionReader(r, int64(c.Start), int64(c.Length))
 }
 
-// Chunker split content with Rabin Fingerprints.
+// Chunker splits content with Rabin Fingerprints.
 type Chunker struct {
 	pol      Pol
 	polShift uint