I've been reading a lot of Plautus lately, but some of the symbols in the metrical appendix don't make sense to me. There is no explanation anywhere in the book about them.
Some of them are easy enough, like tr7 (with the 7 superscript) is trochaic septenarii, ia6 (6 superscript) is iambic senarii, etc.
But there are some like vr, with the r superscript (aulularia 415-446). Or tr sy22metr (22metr being superscript). Or crc + crc (with the c's superscript in both cases). It's clear enough that in the latter two cases tr = trochee and cr = cretic but what's up with the "sy22metr" stuff? And what the heck is "vr"?
What's going on here? What do these symbols mean? The scansion of Plautus is tricky enough without these ambiguous symbols thrown in!