bug#16216: 24.3.50; <control> entries in `ucs-names'

[Drew Adams]

The doc for `insert-char' and `ucs-names' is sketchy.  But it does at
least say that it is about inserting a character "using its UNICODE
name or its code point."

So what are all of those `<control>' character names about?  Many
characters are listed in `ucs-names' as having this same "character
name", `<control>':

 C-x 8 RET TAB C-g
 C-h v ucs-names
 C-s <control> C-s C-s...

And yet, AFAICT, there is no UNICODE character that has the name
`<control>', or even any name that has that as a substring.
http://www.unicode.org/charts/charindex.html

The seems like a bug.  But since the description of `ucs-names' is
so sketchy it's hard to assert that.  If this is not a bug, then:

1. In what way is `<control>' a "CHAR-NAME" for a character with any
   code point?  What does CHAR-NAME mean in this case?

2. What is the purpose of the multiple `<control>' CHAR-NAMEs?

3. Why are different CHAR-CODE values associated with the same
   CHAR-NAME, `<control>'?  What does that mean?

4. Try `C-x 8 RET <contr TAB RET'.  You get only one particular
   character "named" <control>, the one with code point decimal
   159.  That's the character named "APPLICATION PROGRAM COMMAND".
   Why that one?


In GNU Emacs 24.3.50.1 (i686-pc-mingw32)
 of 2013-12-16 on ODIEONE
Bzr revision: 115543 rudalics@gmx.at-20131216095844-lbjh5yerk6ff0tm7
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --prefix=/c/Devel/emacs/binary --enable-checking=yes,glyphs
 'CFLAGS=-O0 -g3' LDFLAGS=-Lc:/Devel/emacs/lib
 CPPFLAGS=-Ic:/Devel/emacs/include'