sorry for two consecutive mails but I hit send before finishing to think... where does is this bit about comments in the manual page? It seems I'm not able to find it (nor the search facility in man too). I'm doing man 5 ldap.conf, the man has all the configuration variables explained well but not a word about where to put comments.

Hash marks as line-long comment indicators is documented in slapd.conf(5). It is also documented in recent 2.4 ldap.conf(5).

p.