How do you play the "opppsite" acciaccatura? And what does it mean by Glissafter?
This appears to be from the manual of a piece of software written for one individual musician to use.
I suggest you contact the author to find out what some of these non-standard terms are supposed to mean. His contact details are in https://mellowood.ca/mma/online-docs/ref/node1.html#SECTION00110000000000000000
To quote that page:
This manual most likely has lots of errors. Spelling, grammar, and probably a number of the examples need fixing
I don't think we can second-guess what he intended to mean here.