In The Unicode Standard, Lisu script implementation is discussed in  Chapter 18 East Asia.

The Old Lisu script was encoded in The Unicode Standard version 5.2 under the name Lisu. The script is encoded in the following block:

BlocksCharacter RangeAdded in Unicode VersionUnicode Chart
Lisu A4D0..A4FF 5.2  UA4D0.pdf

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

2007-09-11 Towards an encoding of the Fraser script in the UCS — Michael Everson ( WG2 N3323,  L2/07-297)

2007-09-15 Fraser’s Lisu orthography: Research notes toward a Unicode encoding — Richard Cook ( WG2 N3326,  L2/07-294)

2007-10-10 Proposal for encoding the Old Lisu script in the BMP of the UCS — China N.B. ( WG2 N3317,  L2/07-357)

2007-12-29 Documentation on legacy encodings of the Old Lisu script — China N.B. ( L2/07-423)

2008-01-28 Proposal for encoding the Old Lisu script in the BMP of the UCS — China N.B. ( L2/08-019)

2009-07-10 Discussion and proposal of default Lisu sort order — Martin Hosken ( L2/09-247)