In The Unicode Standard, Samaritan script implementation is discussed in  Chapter 9 Middle East-I.

Samaritan script was first encoded in The Unicode Standard version 5.2.

Blocks Character Range Added in Unicode Version Unicode Chart
Samaritan 0800..083F 5.2  U0800.pdf

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

2003-06-13 Proposal to encode Samaritan Pentateuch Sign — Peter Constable ( L2/03-206)

2004-05-12 Proposal to add Samaritan Pointing to ISO 10646 — Elaine Keown ( WG2 N2758,  L2/04-159)

2005-07-27 Proposal to encode Samaritan Text symbol — SBL (John Hudson, et al) ( WG2 N3217,  L2/06-245)

2007-07-27 Preliminary proposal to add the Samaritan alphabet to the BMP of the UCS — Michael Everson, Mark Shoulson ( WG2 N3291,  L2/07-231)

2007-08-02 Middle Dots and Don'ts — Ken Whistler ( L2/07-258)

2007-08-05 Non-blank spaces — Asmus Freytag ( L2/07-260)

2008-01-25 Proposal to add the Samaritan alphabet to the BMP of the UCS — Michael Everson, Mark Shoulson ( WG2 N3377,  L2/08-024)

2012-11-03 Sorting all RTL scripts together — Roozbeh Pournader ( L2/12-377)