Jeff Sussna wrote:

Is it possible to add new syntax definitions to LDAP? I've done various searches without unearthing anything. In particular, I'd like to specify a syntax which is "an integer between 0 and 5". Can I do that or do I need to code the enforcement into my client?

Syntaxes currently need to be implemented in C code. You can write your own implementations and dynamically load them as slapd modules.

For your current question, you could just use slapo-constraint(5) instead, using a regex that only accepts a single digit 0-5.