Re: bookmarks for concept index

[Akim Demaille]

|     It is clean, agreed, but pushes too much on the writers IMHO.  
| 
| On the writers?  I thought it would be *easier* for the writers.  Then
| they don't have to know what versions go with what questionable features.

Harder: they can't just simply AC_PREREQ the version they use: they
have to track what features are new.  I'm not even referring to the
cleanups: someday, you will want to remove the @require, but then, which ones?

AC_PREREQ is also cleaner, imho, as it does not spread into the
document, just its prologue.

PS/ You may rename AC_PREREQ if it doesn't fall in the Autotexinfo
conventions :)