diff --git a/site/build.go b/site/build.go
index 2f717d4..8ebf4f0 100644
--- a/site/build.go
+++ b/site/build.go
@@ -13,7 +13,7 @@ import (
 func (s *Site) Clean() error {
 	// TODO PERF when called as part of build, keep files that will be re-generated
 	removeFiles := func(filename string, info os.FileInfo, err error) error {
-		if s.config.Verbose {
+		if s.cfg.Verbose {
 			fmt.Println("rm", filename)
 		}
 		switch {
@@ -25,7 +25,7 @@ func (s *Site) Clean() error {
 			return nil
 		case s.KeepFile(utils.MustRel(s.DestDir(), filename)):
 			return nil
-		case s.config.DryRun:
+		case s.cfg.DryRun:
 			return nil
 		default:
 			// empirically, moving the os.Remove into a goroutine has no performance benefit
@@ -39,7 +39,7 @@ func (s *Site) Clean() error {
 }
 
 func (s *Site) setTimeZone() error {
-	if tz := s.config.Timezone; tz != "" {
+	if tz := s.cfg.Timezone; tz != "" {
 		if _, err := time.LoadLocation(tz); err != nil {
 			fmt.Fprintf(os.Stderr, "%s; using local time zone\n", err)
 		} else if err := os.Setenv("TZ", tz); err != nil {
diff --git a/site/data.go b/site/data.go
index 19825dd..ad5f639 100644
--- a/site/data.go
+++ b/site/data.go
@@ -12,7 +12,7 @@ import (
 
 func (s *Site) readDataFiles() error {
 	s.data = map[string]interface{}{}
-	dataDir := filepath.Join(s.SourceDir(), s.config.DataDir)
+	dataDir := filepath.Join(s.SourceDir(), s.cfg.DataDir)
 	files, err := ioutil.ReadDir(dataDir)
 	if err != nil {
 		if os.IsNotExist(err) {
diff --git a/site/dependencies.go b/site/dependencies.go
index 3e03157..a45c337 100644
--- a/site/dependencies.go
+++ b/site/dependencies.go
@@ -17,9 +17,9 @@ func (s *Site) Exclude(siteRel string) bool {
 	for siteRel != "." {
 		dir, base := filepath.Dir(siteRel), filepath.Base(siteRel)
 		switch {
-		case utils.MatchList(s.config.Include, siteRel):
+		case utils.MatchList(s.cfg.Include, siteRel):
 			return false
-		case utils.MatchList(s.config.Exclude, siteRel):
+		case utils.MatchList(s.cfg.Exclude, siteRel):
 			return true
 		case dir != "." && base[0] == '_':
 			return true
@@ -44,19 +44,19 @@ func (s *Site) Exclude(siteRel string) bool {
 func (s *Site) RequiresFullReload(paths []string) bool {
 	for _, path := range paths {
 		switch {
-		case s.config.IsConfigPath(path):
+		case s.cfg.IsConfigPath(path):
 			return true
 		case s.Exclude(path):
 			continue
-		case !s.config.Incremental:
+		case !s.cfg.Incremental:
 			return true
-		case strings.HasPrefix(path, s.config.DataDir):
+		case strings.HasPrefix(path, s.cfg.DataDir):
 			return true
-		case strings.HasPrefix(path, s.config.IncludesDir):
+		case strings.HasPrefix(path, s.cfg.IncludesDir):
 			return true
-		case strings.HasPrefix(path, s.config.LayoutsDir):
+		case strings.HasPrefix(path, s.cfg.LayoutsDir):
 			return true
-		case strings.HasPrefix(path, s.config.SassDir()):
+		case strings.HasPrefix(path, s.cfg.SassDir()):
 			return true
 		}
 	}
@@ -74,7 +74,7 @@ func (s *Site) affectsBuildFilter(paths []string) []string {
 loop:
 	for _, path := range paths {
 		switch {
-		case s.config.IsConfigPath(path):
+		case s.cfg.IsConfigPath(path):
 			// break
 		case !s.fileAffectsBuild(path):
 			continue loop
@@ -94,9 +94,9 @@ func (s *Site) fileAffectsBuild(rel string) bool {
 		switch {
 		case rel == ".":
 			return true
-		case utils.MatchList(s.config.Include, rel):
+		case utils.MatchList(s.cfg.Include, rel):
 			return true
-		case utils.MatchList(s.config.Exclude, rel):
+		case utils.MatchList(s.cfg.Exclude, rel):
 			return false
 		case strings.HasPrefix(rel, "."):
 			return false
diff --git a/site/dependencies_test.go b/site/dependencies_test.go
index 5675e32..0f43b0e 100644
--- a/site/dependencies_test.go
+++ b/site/dependencies_test.go
@@ -11,7 +11,7 @@ import (
 
 func TestSite_Reloaded(t *testing.T) {
 	s0 := New(config.Flags{})
-	s0.config.Incremental = true
+	s0.cfg.Incremental = true
 	s1, _ := s0.Reloaded([]string{})
 	require.Equal(t, s0, s1)
 
@@ -30,7 +30,7 @@ func TestSite_RequiresFullReload(t *testing.T) {
 	// require.False(t, s.RequiresFullReload([]string{"_site"}))
 	// require.False(t, s.RequiresFullReload([]string{"_site/index.html"}))
 
-	s.config.Incremental = true
+	s.cfg.Incremental = true
 	require.False(t, s.RequiresFullReload([]string{}))
 	require.False(t, s.RequiresFullReload([]string{"file.md"}))
 	require.True(t, s.RequiresFullReload([]string{"_config.yml"}))
diff --git a/site/drop.go b/site/drop.go
index 7b36440..4dbc82a 100644
--- a/site/drop.go
+++ b/site/drop.go
@@ -25,7 +25,7 @@ func (s *Site) initializeDrop() error {
 	for _, c := range s.Collections {
 		docs = append(docs, c.Pages()...)
 	}
-	drop := templates.MergeVariableMaps(s.config.Variables(), map[string]interface{}{
+	drop := templates.MergeVariableMaps(s.cfg.Variables(), map[string]interface{}{
 		"collections":  s.collectionDrops(),
 		"data":         s.data,
 		"documents":    docs,
diff --git a/site/read.go b/site/read.go
index 6e25606..07d7df2 100644
--- a/site/read.go
+++ b/site/read.go
@@ -16,17 +16,17 @@ import (
 // FromDirectory reads the configuration file, if it exists.
 func FromDirectory(dir string, flags config.Flags) (*Site, error) {
 	s := New(flags)
-	if err := s.config.FromDirectory(dir); err != nil {
+	if err := s.cfg.FromDirectory(dir); err != nil {
 		return nil, err
 	}
-	s.config.ApplyFlags(s.flags)
+	s.cfg.ApplyFlags(s.flags)
 	return s, nil
 }
 
 // Read loads the site data and files.
 func (s *Site) Read() error {
 	s.Routes = make(map[string]pages.Document)
-	plugins.Install(s.config.Plugins, s)
+	plugins.Install(s.cfg.Plugins, s)
 	if err := s.findTheme(); err != nil {
 		return err
 	}
@@ -65,7 +65,7 @@ func (s *Site) readFiles(dir, base string) error {
 		case strings.HasPrefix(rel, "_"):
 			return nil
 		}
-		defaultFrontmatter := s.config.GetFrontMatterDefaults("", rel)
+		defaultFrontmatter := s.cfg.GetFrontMatterDefaults("", rel)
 		d, err := pages.NewFile(s, filename, filepath.ToSlash(rel), defaultFrontmatter)
 		if err != nil {
 			return utils.WrapPathError(err, filename)
@@ -81,7 +81,7 @@ func (s *Site) readFiles(dir, base string) error {
 // AddDocument adds a document to the site's fields.
 // It ignores unpublished documents unless config.Unpublished is true.
 func (s *Site) AddDocument(d pages.Document, output bool) {
-	if d.Published() || s.config.Unpublished {
+	if d.Published() || s.cfg.Unpublished {
 		s.docs = append(s.docs, d)
 		if output {
 			s.Routes[d.Permalink()] = d
@@ -93,7 +93,7 @@ func (s *Site) AddDocument(d pages.Document, output bool) {
 // It adds each collection's pages to the site map, and creates a template site variable for each collection.
 func (s *Site) ReadCollections() (err error) {
 	var cols []*collection.Collection
-	for name, data := range s.config.Collections {
+	for name, data := range s.cfg.Collections {
 		c := collection.New(s, name, data)
 		cols = append(cols, c)
 		err = c.ReadPages()
diff --git a/site/site.go b/site/site.go
index e2a0d39..3adbf07 100644
--- a/site/site.go
+++ b/site/site.go
@@ -17,12 +17,12 @@ import (
 // Site is a Jekyll site.
 type Site struct {
 	Collections []*collection.Collection
-	Routes      map[string]pages.Document // URL path -> Document, only for output pages
+	Routes      map[string]pages.Document // URL path -> Document; only for output pages
 
-	config   config.Config
-	data     map[string]interface{}
-	flags    config.Flags
-	themeDir string
+	cfg      config.Config
+	data     map[string]interface{} // from _data files
+	flags    config.Flags           // command-line flags, override config files
+	themeDir string                 // absolute path to theme directory
 
 	docs               []pages.Document // all documents, whether or not they are output
 	nonCollectionPages []pages.Page
@@ -35,14 +35,14 @@ type Site struct {
 }
 
 // SourceDir returns the site source directory.
-func (s *Site) SourceDir() string { return s.config.Source }
+func (s *Site) SourceDir() string { return s.cfg.Source }
 
 // DestDir returns the site destination directory.
 func (s *Site) DestDir() string {
-	if filepath.IsAbs(s.config.Destination) {
-		return s.config.Destination
+	if filepath.IsAbs(s.cfg.Destination) {
+		return s.cfg.Destination
 	}
-	return filepath.Join(s.config.Source, s.config.Destination)
+	return filepath.Join(s.cfg.Source, s.cfg.Destination)
 }
 
 // OutputDocs returns a list of output pages.
@@ -75,11 +75,11 @@ func (s *Site) AbsDir() string {
 
 // Config is in the collection.Site interface.
 func (s *Site) Config() *config.Config {
-	return &s.config
+	return &s.cfg
 }
 
 func (s *Site) runHooks(h func(plugins.Plugin) error) error {
-	for _, name := range s.config.Plugins {
+	for _, name := range s.cfg.Plugins {
 		p, ok := plugins.Lookup(name)
 		if ok {
 			if err := h(p); err != nil {
@@ -100,16 +100,16 @@ func (s *Site) PathPrefix() string { return "" }
 
 // New creates a new site record, initialized with the site defaults.
 func New(flags config.Flags) *Site {
-	s := &Site{config: config.Default(), flags: flags}
-	s.config.ApplyFlags(flags)
+	s := &Site{cfg: config.Default(), flags: flags}
+	s.cfg.ApplyFlags(flags)
 	return s
 }
 
 // SetAbsoluteURL overrides the loaded configuration.
 // The server uses this.
 func (s *Site) SetAbsoluteURL(url string) {
-	s.config.AbsoluteURL = url
-	s.config.Set("url", url)
+	s.cfg.AbsoluteURL = url
+	s.cfg.Set("url", url)
 	if s.drop != nil {
 		s.drop["url"] = url
 	}
@@ -126,7 +126,7 @@ func (s *Site) FilenameURLs() map[string]string {
 
 // KeepFile returns a boolean indicating that clean should leave the file in the destination directory.
 func (s *Site) KeepFile(filename string) bool {
-	return utils.SearchStrings(s.config.KeepFiles, filename)
+	return utils.SearchStrings(s.cfg.KeepFiles, filename)
 }
 
 // FilePathPage returns a Page, give a file path relative to site source directory.
@@ -171,7 +171,7 @@ func (s *Site) initializeRenderers() (err error) {
 		RelativeFilenameToURL: s.FilenameURLPath,
 		ThemeDir:              s.themeDir,
 	}
-	s.renderer, err = renderers.New(s.config, options)
+	s.renderer, err = renderers.New(s.cfg, options)
 	if err != nil {
 		return err
 	}
@@ -188,7 +188,7 @@ func (s *Site) RelativePath(path string) string {
 			return rel
 		}
 	}
-	return utils.MustRel(s.config.Source, path)
+	return utils.MustRel(s.cfg.Source, path)
 }
 
 // URLPage returns the page that will be served at URL
diff --git a/site/site_test.go b/site/site_test.go
index 2ebd88a..0d77e39 100644
--- a/site/site_test.go
+++ b/site/site_test.go
@@ -17,8 +17,8 @@ func TestKeepFile(t *testing.T) {
 
 func TestExclude(t *testing.T) {
 	s := New(config.Flags{})
-	s.config.Exclude = append(s.config.Exclude, "exclude/")
-	s.config.Include = append(s.config.Include, ".include/")
+	s.cfg.Exclude = append(s.cfg.Exclude, "exclude/")
+	s.cfg.Include = append(s.cfg.Include, ".include/")
 	require.False(t, s.Exclude("."))
 	require.True(t, s.Exclude(".git"))
 	require.True(t, s.Exclude(".dir"))
diff --git a/site/theme.go b/site/theme.go
index 9624730..066f66b 100644
--- a/site/theme.go
+++ b/site/theme.go
@@ -10,19 +10,19 @@ import (
 )
 
 func (s *Site) findTheme() error {
-	if s.config.Theme == "" {
+	if s.cfg.Theme == "" {
 		return nil
 	}
 	exe, err := exec.LookPath("bundle")
 	if err != nil {
 		log.Fatal("bundle is not in your PATH", err)
 	}
-	cmd := exec.Command(exe, "show", s.config.Theme) // nolint: gas
+	cmd := exec.Command(exe, "show", s.cfg.Theme) // nolint: gas
 	cmd.Dir = s.AbsDir()
 	out, err := cmd.CombinedOutput()
 	if err != nil {
 		if os.IsNotExist(err) {
-			return fmt.Errorf("the %s theme could not be found", s.config.Theme)
+			return fmt.Errorf("the %s theme could not be found", s.cfg.Theme)
 		}
 		return err
 	}
diff --git a/site/watch.go b/site/watch.go
index ddbd67e..0619238 100644
--- a/site/watch.go
+++ b/site/watch.go
@@ -50,7 +50,7 @@ func (s *Site) WatchFiles() (<-chan FilesEvent, error) {
 
 func (s *Site) makeFileWatcher() (<-chan string, error) {
 	switch {
-	case s.config.ForcePolling:
+	case s.cfg.ForcePolling:
 		return s.makePollingWatcher()
 	default:
 		return s.makeEventWatcher()
@@ -88,7 +88,7 @@ func (s *Site) makePollingWatcher() (<-chan string, error) {
 	if err := w.AddRecursive(sourceDir); err != nil {
 		return nil, err
 	}
-	for _, path := range s.config.Exclude {
+	for _, path := range s.cfg.Exclude {
 		if err := w.Ignore(filepath.Join(sourceDir, path)); err != nil {
 			return nil, err
 		}
diff --git a/site/write.go b/site/write.go
index 073d25d..2e30b9d 100644
--- a/site/write.go
+++ b/site/write.go
@@ -60,10 +60,10 @@ func (s *Site) WriteDoc(d pages.Document) error {
 		rel = filepath.Join(rel, "index.html")
 	}
 	to := filepath.Join(s.DestDir(), rel)
-	if s.config.Verbose {
+	if s.cfg.Verbose {
 		fmt.Println("create", to, "from", d.SourcePath())
 	}
-	if s.config.DryRun {
+	if s.cfg.DryRun {
 		// FIXME render the page, just don't write it
 		return nil
 	}