diff --git a/.gitignore b/.gitignore
index c450f48..9632b28 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 mycorrhiza
+hyphae/*.gog
diff --git a/http_readers.go b/http_readers.go
index 7978e69..9cd4c69 100644
--- a/http_readers.go
+++ b/http_readers.go
@@ -11,6 +11,7 @@ import (
 
 	"github.com/bouncepaw/mycorrhiza/history"
 	"github.com/bouncepaw/mycorrhiza/markup"
+	"github.com/bouncepaw/mycorrhiza/mimetype"
 	"github.com/bouncepaw/mycorrhiza/templates"
 	"github.com/bouncepaw/mycorrhiza/tree"
 	"github.com/bouncepaw/mycorrhiza/user"
@@ -71,7 +72,7 @@ func handlerBinary(w http.ResponseWriter, rq *http.Request) {
 	hyphaName := HyphaNameFromRq(rq, "binary")
 	if data, ok := HyphaStorage[hyphaName]; ok {
 		log.Println("Serving", data.binaryPath)
-		w.Header().Set("Content-Type", ExtensionToMime(filepath.Ext(data.binaryPath)))
+		w.Header().Set("Content-Type", mimetype.FromExtension(filepath.Ext(data.binaryPath)))
 		http.ServeFile(w, rq, data.binaryPath)
 	}
 }
diff --git a/hypha.go b/hypha.go
index be7fef4..82fe103 100644
--- a/hypha.go
+++ b/hypha.go
@@ -13,6 +13,7 @@ import (
 	"github.com/bouncepaw/mycorrhiza/history"
 	"github.com/bouncepaw/mycorrhiza/hyphae"
 	"github.com/bouncepaw/mycorrhiza/markup"
+	"github.com/bouncepaw/mycorrhiza/mimetype"
 	"github.com/bouncepaw/mycorrhiza/user"
 	"github.com/bouncepaw/mycorrhiza/util"
 )
@@ -114,7 +115,7 @@ func UploadBinary(hyphaName, mime string, file multipart.File, u *user.User) *hi
 	if err != nil {
 		return hop.WithError(err).Apply()
 	}
-	return uploadHelp(hop, hyphaName, MimeToExtension(mime), data, u)
+	return uploadHelp(hop, hyphaName, mimetype.ToExtension(mime), data, u)
 }
 
 // DeleteHypha deletes hypha and makes a history record about that.
@@ -254,48 +255,6 @@ func binaryHtmlBlock(hyphaName string, hd *HyphaData) string {
 	}
 }
 
-// Index finds all hypha files in the full `path` and saves them to HyphaStorage. This function is recursive.
-func Index(path string) {
-	nodes, err := ioutil.ReadDir(path)
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	for _, node := range nodes {
-		// If this hypha looks like it can be a hypha path, go deeper. Do not touch the .git and static folders for they have an admnistrative importance!
-		if node.IsDir() && isCanonicalName(node.Name()) && node.Name() != ".git" && node.Name() != "static" {
-			Index(filepath.Join(path, node.Name()))
-			continue
-		}
-
-		var (
-			hyphaPartPath           = filepath.Join(path, node.Name())
-			hyphaName, isText, skip = DataFromFilename(hyphaPartPath)
-			hyphaData               *HyphaData
-		)
-		if !skip {
-			// Reuse the entry for existing hyphae, create a new one for those that do not exist yet.
-			if hd, ok := HyphaStorage[hyphaName]; ok {
-				hyphaData = hd
-			} else {
-				hyphaData = &HyphaData{}
-				HyphaStorage[hyphaName] = hyphaData
-				hyphae.IncrementCount()
-			}
-			if isText {
-				hyphaData.textPath = hyphaPartPath
-			} else {
-				// Notify the user about binary part collisions. It's a design decision to just use any of them, it's the user's fault that they have screwed up the folder structure, but the engine should at least let them know, right?
-				if hyphaData.binaryPath != "" {
-					log.Println("There is a file collision for binary part of a hypha:", hyphaData.binaryPath, "and", hyphaPartPath, "-- going on with the latter")
-				}
-				hyphaData.binaryPath = hyphaPartPath
-			}
-		}
-
-	}
-}
-
 // FetchTextPart tries to read text file in the `d`. If there is no file, empty string is returned.
 func FetchTextPart(d *HyphaData) (string, error) {
 	if d.textPath == "" {
@@ -327,3 +286,45 @@ func setHeaderLinks() {
 		}
 	}
 }
+
+// Index finds all hypha files in the full `path` and saves them to HyphaStorage. This function is recursive.
+func Index(path string) {
+	nodes, err := ioutil.ReadDir(path)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for _, node := range nodes {
+		// If this hypha looks like it can be a hypha path, go deeper. Do not touch the .git and static folders for they have an admnistrative importance!
+		if node.IsDir() && isCanonicalName(node.Name()) && node.Name() != ".git" && node.Name() != "static" {
+			Index(filepath.Join(path, node.Name()))
+			continue
+		}
+
+		var (
+			hyphaPartPath           = filepath.Join(path, node.Name())
+			hyphaName, isText, skip = mimetype.DataFromFilename(hyphaPartPath)
+			hyphaData               *HyphaData
+		)
+		if !skip {
+			// Reuse the entry for existing hyphae, create a new one for those that do not exist yet.
+			if hd, ok := HyphaStorage[hyphaName]; ok {
+				hyphaData = hd
+			} else {
+				hyphaData = &HyphaData{}
+				HyphaStorage[hyphaName] = hyphaData
+				hyphae.IncrementCount()
+			}
+			if isText {
+				hyphaData.textPath = hyphaPartPath
+			} else {
+				// Notify the user about binary part collisions. It's a design decision to just use any of them, it's the user's fault that they have screwed up the folder structure, but the engine should at least let them know, right?
+				if hyphaData.binaryPath != "" {
+					log.Println("There is a file collision for binary part of a hypha:", hyphaData.binaryPath, "and", hyphaPartPath, "-- going on with the latter")
+				}
+				hyphaData.binaryPath = hyphaPartPath
+			}
+		}
+
+	}
+}
diff --git a/hyphae/hypha.go b/hyphae/hypha.go
deleted file mode 100644
index d70cd1e..0000000
--- a/hyphae/hypha.go
+++ /dev/null
@@ -1,21 +0,0 @@
-package hyphae
-
-// TODO: do
-import ()
-
-type Hypha struct {
-	Name       string
-	Exists     bool
-	TextPath   string
-	BinaryPath string
-	OutLinks   []string
-	BackLinks  []string
-}
-
-// AddHypha adds a hypha named `name` with such `textPath` and `binaryPath`. Both paths can be empty. Does //not// check for hypha's existence beforehand. Count is handled.
-func AddHypha(name, textPath, binaryPath string) {
-}
-
-// DeleteHypha clears both paths and all out-links from the named hypha and marks it as non-existent. It does not actually delete it from the memdb. Count is handled.
-func DeleteHypha(name string) {
-}
diff --git a/main.go b/main.go
index c87c96e..f16eaa3 100644
--- a/main.go
+++ b/main.go
@@ -15,6 +15,7 @@ import (
 
 	"github.com/bouncepaw/mycorrhiza/history"
 	"github.com/bouncepaw/mycorrhiza/hyphae"
+	"github.com/bouncepaw/mycorrhiza/mimetype"
 	"github.com/bouncepaw/mycorrhiza/templates"
 	"github.com/bouncepaw/mycorrhiza/user"
 	"github.com/bouncepaw/mycorrhiza/util"
@@ -64,7 +65,7 @@ func handlerList(w http.ResponseWriter, rq *http.Request) {
 		u         = user.FromRequest(rq)
 	)
 	for hyphaName, data := range HyphaStorage {
-		tbody += templates.HyphaListRowHTML(hyphaName, ExtensionToMime(filepath.Ext(data.binaryPath)), data.binaryPath != "")
+		tbody += templates.HyphaListRowHTML(hyphaName, mimetype.FromExtension(filepath.Ext(data.binaryPath)), data.binaryPath != "")
 	}
 	util.HTTP200Page(w, base("List of pages", templates.HyphaListHTML(tbody, pageCount), u))
 }
diff --git a/mime.go b/mime.go
deleted file mode 100644
index c16eebe..0000000
--- a/mime.go
+++ /dev/null
@@ -1,62 +0,0 @@
-package main
-
-import (
-	"path/filepath"
-	"strings"
-)
-
-func MimeToExtension(mime string) string {
-	mm := map[string]string{
-		"application/octet-stream": "bin",
-		"image/jpeg":               "jpg",
-		"image/gif":                "gif",
-		"image/png":                "png",
-		"image/webp":               "webp",
-		"image/svg+xml":            "svg",
-		"image/x-icon":             "ico",
-		"application/ogg":          "ogg",
-		"video/webm":               "webm",
-		"audio/mp3":                "mp3",
-		"video/mp4":                "mp4",
-	}
-	if ext, ok := mm[mime]; ok {
-		return "." + ext
-	}
-	return ".bin"
-}
-
-func ExtensionToMime(ext string) string {
-	mm := map[string]string{
-		".bin":  "application/octet-stream",
-		".jpg":  "image/jpeg",
-		".jpeg": "image/jpeg",
-		".gif":  "image/gif",
-		".png":  "image/png",
-		".webp": "image/webp",
-		".svg":  "image/svg+xml",
-		".ico":  "image/x-icon",
-		".ogg":  "application/ogg",
-		".webm": "video/webm",
-		".mp3":  "audio/mp3",
-		".mp4":  "video/mp4",
-	}
-	if mime, ok := mm[ext]; ok {
-		return mime
-	}
-	return "application/octet-stream"
-}
-
-// DataFromFilename fetches all meta information from hypha content file with path `fullPath`. If it is not a content file, `skip` is true, and you are expected to ignore this file when indexing hyphae. `name` is name of the hypha to which this file relates. `isText` is true when the content file is text, false when is binary. `mimeId` is an integer representation of content type. Cast it to TextType if `isText == true`, cast it to BinaryType if `isText == false`.
-func DataFromFilename(fullPath string) (name string, isText bool, skip bool) {
-	shortPath := strings.TrimPrefix(fullPath, WikiDir)[1:]
-	ext := filepath.Ext(shortPath)
-	name = CanonicalName(strings.TrimSuffix(shortPath, ext))
-	switch ext {
-	case ".myco":
-		isText = true
-	case "", shortPath:
-		skip = true
-	}
-
-	return
-}
diff --git a/mimetype/mime.go b/mimetype/mime.go
new file mode 100644
index 0000000..7e18ca7
--- /dev/null
+++ b/mimetype/mime.go
@@ -0,0 +1,68 @@
+package mimetype
+
+import (
+	"path/filepath"
+	"strings"
+
+	"github.com/bouncepaw/mycorrhiza/util"
+)
+
+// ToExtension returns dotted extension for given mime-type.
+func ToExtension(mime string) string {
+	if ext, ok := mapMime2Ext[mime]; ok {
+		return "." + ext
+	}
+	return ".bin"
+}
+
+// FromExtension returns mime-type for given extension. The extension must start with a dot.
+func FromExtension(ext string) string {
+	if mime, ok := mapExt2Mime[ext]; ok {
+		return mime
+	}
+	return "application/octet-stream"
+}
+
+// DataFromFilename fetches all meta information from hypha content file with path `fullPath`. If it is not a content file, `skip` is true, and you are expected to ignore this file when indexing hyphae. `name` is name of the hypha to which this file relates. `isText` is true when the content file is text, false when is binary.
+func DataFromFilename(fullPath string) (name string, isText bool, skip bool) {
+	shortPath := util.ShorterPath(fullPath)
+	ext := filepath.Ext(shortPath)
+	name = util.CanonicalName(strings.TrimSuffix(shortPath, ext))
+	switch ext {
+	case ".myco":
+		isText = true
+	case "", shortPath:
+		skip = true
+	}
+
+	return
+}
+
+var mapMime2Ext = map[string]string{
+	"application/octet-stream": "bin",
+	"image/jpeg":               "jpg",
+	"image/gif":                "gif",
+	"image/png":                "png",
+	"image/webp":               "webp",
+	"image/svg+xml":            "svg",
+	"image/x-icon":             "ico",
+	"application/ogg":          "ogg",
+	"video/webm":               "webm",
+	"audio/mp3":                "mp3",
+	"video/mp4":                "mp4",
+}
+
+var mapExt2Mime = map[string]string{
+	".bin":  "application/octet-stream",
+	".jpg":  "image/jpeg",
+	".jpeg": "image/jpeg",
+	".gif":  "image/gif",
+	".png":  "image/png",
+	".webp": "image/webp",
+	".svg":  "image/svg+xml",
+	".ico":  "image/x-icon",
+	".ogg":  "application/ogg",
+	".webm": "video/webm",
+	".mp3":  "audio/mp3",
+	".mp4":  "video/mp4",
+}
diff --git a/util/util.go b/util/util.go
index c977992..acf0eec 100644
--- a/util/util.go
+++ b/util/util.go
@@ -4,6 +4,7 @@ import (
 	"crypto/rand"
 	"encoding/hex"
 	"net/http"
+	"regexp"
 	"strings"
 )
 
@@ -65,3 +66,16 @@ func BeautifulName(uglyName string) string {
 	}
 	return strings.Title(strings.ReplaceAll(uglyName, "_", " "))
 }
+
+// CanonicalName makes sure the `name` is canonical. A name is canonical if it is lowercase and all spaces are replaced with underscores.
+func CanonicalName(name string) string {
+	return strings.ToLower(strings.ReplaceAll(name, " ", "_"))
+}
+
+// HyphaPattern is a pattern which all hyphae must match.
+var HyphaPattern = regexp.MustCompile(`[^?!:#@><*|"\'&%{}]+`)
+
+// IsCanonicalName checks if the `name` is canonical.
+func IsCanonicalName(name string) bool {
+	return HyphaPattern.MatchString(name)
+}