I keep coming across a letterlike symbol based on the letter p. In going through my collections, I found it listed in a table of symbols in an excerpt from the US Government Printing office style manual from 1984.
That symbol is named 'per'
The _per_ sign can also be found (along with other symbols not currently in Unicode) in the most recent U.S. Government Printing Office Style Manual at http://www.gpoaccess.gov/stylemanual/2000/chap10.pdf.
It also appears along with other symbols used in the OED at http://dictionary.oed.com/public/help/Advanced/symbols.htm#mod1letter. (Again, not all these symbols are currently part of Unicode.)
I know I've encountered it elsewhere, but I think only in similar lists of symbols.
It is probably the sign indicated by the editors of The Papers of George Washington at http://gwpapers.virginia.edu/search/index.html:
<< The ampersand has been retained and the thorn transcribed as "th." The symbol for per ($PR) is used when it appears in the manuscript. >>
Unfortunately this ($PR) does not appear in any of the transcription or facsimile examples on the website.
But at http://www.roma.unisa.edu.au/07305/symbols.htm#Percent part of an Italian manuscript of 1684 is shown in which an early form of the percent sign is preceded by what seems to be this same per sign.
The graphic can be seen more clearly at http://www.roma.unisa.edu.au/07305/Symbolsfolder/S406.JPG.
I suspect its origin is the _p_ with a bar through its descender which was the standard medieval character for "per".
See http://www.rootsweb.com/~chevaud/abbrev.htm for a version with a single loop, seemingly a calligraphic development of the version found at http://www.lib.umich.edu/eebo/docs/dox/instruct.html called "&abper".
See also both http://www.hum.ku.dk/ami/handbook/chapter4.html (and search on "persarum") and http://helmer.hit.uib.no/mufi/proposal/range9-v2.htmlhttp://helmer.hit.uib.no/mufi/proposal/range9-v2.html (and search on "&pbardes").
But the difference between medieval and more modern glyphs is great and a _p_ with a bar though the descender has also been used to indicate a fricative labial or an _f_-sound in some phonetic and transliteration traditions.
Accordingly it might be best to code two symbols, a _p_ with a bar through the descender (with corresponding uppercase) to indicate the both medieval _per_ sign and modern phonetic ussage of barred _p_ and a separate character for the more modern swirly descendant of the medieval _per_ sign.
Jim Allan
