Siegfried Richter, the INTF Coptic expert, just informed me that Münster has launched an online index of Coptic New Testament manuscripts (here). The searchable database is helpful for determining which and how many manuscripts are extant for a particular text. Additionally, PDFs listing Greek-Coptic diglots and comparing dates are also offered.
There are currently two sets of sigla used to describe Coptic biblical manuscripts. The first was developed by Gerd Mink and Franz-Jürgen Schmitz, published in:
Schmitz, Franz-Jürgen, and Gerd Mink, eds. Liste Der Koptischen Handschriften Des Neuen Testaments: Sahidischen Handschriften der Evangelien. 3 vols. Arbeiten zur neutestamentlichen Textforschung 8, 13, 15. Berlin: de Gruyter, 1986, 1989, 1991.
The Münster-educated Austrian Coptologist, Karlheinz Schüssler, produced a second set of sigla, which unfortunately used the exact same appearance in his Biblia Coptica fascicles:
Schüssler, Karlheinz, ed. Biblia Coptica: Die koptischen Bibeltexte. 9 fasc/3 vol. Wiesbaden: Harrassowitz, 1995–2007.
Schüssler's webpage contains images of the many manuscripts contained in his list, as well as transcriptions of the more important witnesses to Sahidic John.
As a result, the siglum "sa 1" may represent either a Genesis manuscript (Schüssler) or a manuscript with Luke, Mark and John (SMR).
I encourage scholars to employ the SMR (Schmitz-Mink-Richter) sigla, and this online list is one of the main reasons. The list is bi-annually updated, is free, and reflects the longterm commitment of the INTF to Coptic Bible. Hopefully, the SMR list will eventually incorporate Old Testament manuscripts.
Thanks to Siegfried and his assistant Matthias Schulz for this new resource, and also to the larger INTF team for their forward-looking use of the internet.