glossary-content.txt: rephrase magic signature part

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/glossary-content.txt

@@ -323,24 +323,26 @@ including Documentation/chapter_1/figure_1.jpg.
 A pathspec that begins with a colon `:` has special meaning.  In the
 short form, the leading colon `:` is followed by zero or more "magic
 signature" letters (which optionally is terminated by another colon `:`),
-and the remainder is the pattern to match against the path. The optional
-colon that terminates the "magic signature" can be omitted if the pattern
-begins with a character that cannot be a "magic signature" and is not a
-colon.
+and the remainder is the pattern to match against the path.
+The "magic signature" consists of ASCII symbols that are neither
+alphanumeric, glob, regex special charaters nor colon.
+The optional colon that terminates the "magic signature" can be
+omitted if the pattern begins with a character that does not belong to
+"magic signature" symbol set and is not a colon.
 +
 In the long form, the leading colon `:` is followed by a open
 parenthesis `(`, a comma-separated list of zero or more "magic words",
 and a close parentheses `)`, and the remainder is the pattern to match
 against the path.
 +
-The "magic signature" consists of an ASCII symbol that is not
-alphanumeric.
+A pathspec with only a colon means "there is no pathspec". This form
+should not be combined with other pathspec.
 +
 --
-top `/`;;
-	The magic word `top` (mnemonic: `/`) makes the pattern match
-	from the root of the working tree, even when you are running
-	the command from inside a subdirectory.
+top;;
+	The magic word `top` (magic signature: `/`) makes the pattern
+	match from the root of the working tree, even when you are
+	running the command from inside a subdirectory.
 
 literal;;
 	Wildcards in the pattern such as `*` or `?` are treated
@@ -378,13 +380,6 @@ full pathname may have special meaning:
 +
 Glob magic is incompatible with literal magic.
 --
-+
-Currently only the slash `/` is recognized as the "magic signature",
-but it is envisioned that we will support more types of magic in later
-versions of Git.
-+
-A pathspec with only a colon means "there is no pathspec". This form
-should not be combined with other pathspec.
 
 [[def_parent]]parent::
 	A <<def_commit_object,commit object>> contains a (possibly empty) list