In Latin scribal conventions, when the reverse-c shape is in-line with the rest of the text (not superscripted), it means something different from the apostrophe "cap" shape (the curved macron). It is the 13th-century form of "con", but a few scribes were still using it in the late 15th century (see example c. 1479).
Here are some examples. Sometimes it is quite smooth and round, but I'm too tired to dig up a good example right now, these are a bit more angular but hopefully good enough to illustrate the basic use of the shape:
It is similar in meaning to EVA-y at the beginning of words (con/com) but more specific (usually con). It was fading away by the later 14th century and was replaced by the EVA-y shape (it looks more specifically like the number 9). In fact, if the tail of the reverse-c is lengthened, it resembles EVA-y, as can be seen by some of the examples. The transitional shape was a more open "9" shape (in-between a reverse-c and a "9" char).
You can see from the examples that include both the reverse-c at the beginnings and the EVA-y shape at the ends (sometimes superscripted) that they used to make more of a distinction between the two shapes. Eventually they didn't do this any more and used EVA-y both beginning and end.
Note also the many apostrophes: macrons, curved macrons (caps), "smoke" apostrophes, all very common.
The
Tacuinum Sanitatis script uses the reverse-c abbreviation with regularity. If I remember correctly, it is the Veneto/Lombardy version (c. 1450) that does so.
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