On the Syriac keyboard, as well as at CAL <!-- m --><a class="postlink" href="http://cal.huc.edu/searching/fullbrowser.html">http://cal.huc.edu/searching/fullbrowser.html</a><!-- m --> (CAL Code P), I see this backwards Pe, it's not part of 22 letters, what is that symbol about?
It's used in Christian Palestinian Aramaic which is a Western Aramaic dialect closely related to Galilean Aramaic and Samaritan Aramaic, but written in a rather special, distinct form of Estrangela.
It indicates a p sound, as pe on its own came to represent f exclusively in that dialect. You don't come across it very often; only when transliterating Greek words, really.
Peace,
-Steve
Thank you Steve. Looks like a situation similar to Arabic fa'.
Based on Thackston's Introduction To Syriac, it would seem that Eastern Syriac sounds are all to be found among the Arabic sounds - with Pe being unique to Aramaic and maybe some vowel variations.