Need help with the Latin course definitions

I am using Memrise to learn Latin and have difficulty understanding the grammar abbreviations like 1DSN and the like. I would appreciate a link to a source explaining these. Thanks a million!


Please provide a link to the course. Abbreviations are not standardized. However, some common ones are:

N: Noun
V: Verb
1,2,3,4 etc: declension or conjugation class