1. Introduction

   The Application Configuration Access Protocol ACAP [11] specification
   introduced the concept of a comparator (which we call collation in
   this document), but failed to create an IANA registry.  With the
   introduction of stringprep [6] and the Unicode Collation Algorithm
   [7], it is now time to create that registry and populate it with some
   initial values appropriate for an international community.  This
   specification replaces and generalizes the definition of a comparator
   in ACAP, and creates a collation registry.

1.1. Conventions Used in This Document

   The key words "MUST", "MUST NOT", "SHOULD", "SHOULD NOT", and "MAY"
   in this document are to be interpreted as defined in "Key words for
   use in RFCs to Indicate Requirement Levels" [1].

   The attribute syntax specifications use the Augmented Backus-Naur
   Form (ABNF) [2] notation, including the core rules defined in
   Appendix A.  The ABNF production "Language-tag" is imported from
   Language Tags [5] and "reg-name" from URI: Generic Syntax [4].