In The Unicode Standard, Pahawh Hmong script implementation is discussed in  Chapter 16 Southeast Asia.

The Pahawh Hmong script was encoded in The Unicode Standard version 7.0. The script is now encoded in the following block:

BlocksCharacter RangeAdded in Unicode VersionUnicode chart
Pahawh Hmong 16B00..16B8F 7.0  U16B00.pdf

A number of proposals for its inclusion have been submitted to the Unicode Technical Committee and WG2:

2009-05-04 Preliminary proposal to encode the Pahawh Hmong script in the UCS — Michael Everson ( WG2 N3616,  L2/09-145)

2009-09-14 Proposal to encode the Pahawh Hmong script in the UCS — Michael Everson ( WG2 N3667,  L2/09-252)

2012-01-20 Final proposal to encode the Pahawh Hmong script in the UCS — Michael Everson ( WG2 N4175,  L2/12-013)

2012-07-24 Additional evidence of use of Pahawh Hmong clan logographs — Michael Everson ( WG2 N4298,  L2/12-271)