Didier Verna <verna(a)inf.enst.fr&gt; writes: Hmm. In that case, obsolete that name, and use a totally different name for the new macro, along with the REGEXP flag. That's perfectly fine, as long as you take care not to hose the users. Not really. `concat' had this warning for ages: Do not use individual integers as arguments! The behavior of `concat' in that case will be changed later! If your program passes an integer as an argument to `concat', you should change it right away not to do so. Also, the old code using `concat' fails with a clear error message. In this case, the old code saying, for instance: (with-caps-disable-folding STRING FORM1 FORM2 ...) *No* error will be signaled, but FORM1 will be evaluated and used as the REGEXP flag. Subtle and evil. Neither am I, and that's the whole point. For all I know, lots of code might use it. I know I liked it, and used it in my internal customizations. It is very complicated to detect. I really think keeping the old macro and giving the new one another name is the easiest path in this case. It's been done countless times (add-menu -> add-submenu, etc.) and the compatibility effort is in most cases worth it. Breaking backward compatibility is acceptable, but breaking it subtly is not. All IMHO, of course. Yes, that's what I meant by "modification" of it. You mean the other way around: hooks->hook? -- Hrvoje Niksic <hniksic(a)srce.hr&gt; | Student at FER Zagreb, Croatia --------------------------------+-------------------------------- Thou Who might be our Father Who perhaps may be in Heaven... -- Roger Zelazny