version-control customization

[Andreas Roehler]

Emacs Manual says
,----
| 23.3.2.1 Numbered Backups
| .........................
|
| The choice of single backup file or multiple numbered backup files is
| controlled by the variable `version-control'.  Its possible values are:
|
| `t'
|      Make numbered backups.
|
| `nil'
|      Make numbered backups for files that have numbered backups already.
|      Otherwise, make single backups.
|
| `never'
|      Never make numbered backups; always make single backups.
`----

which at a first glance seems not congruent with menu
from files.el

,----
| (defcustom version-control nil
|   "*Control use of version numbers for backup files.
| t means make numeric backup versions unconditionally.
| nil means make them for files that have some already.
| `never' means do not make them."
|   :type '(choice (const :tag "Never" never)
|          (const :tag "If existing" nil)
|          (other :tag "Always" t))
`----

i.e. user sees only tag names while customizing, not
the actual or choosen values.


As providing a hint inside the tag as shown below.

(const :tag "If existing (nil)" nil)
        (other :tag "Always (t)" t))

may lead into confusion--"If existing" isn't
"nil" in the word sense--probably the cleanest way would be to put "If
existing" the way as "Never" is handled - asigning a
special symbol here, for example "Conditional".

__
Andreas Roehler