I've been skimming a bunch of 16th–17th century English books with blackletter type recently, and the relation of ꝛ to r, ſ to s, v to u, j to i, ʒ vs z, etc. s

I've been skimming a bunch of 16th–17th century English books with blackletter type recently, and the relation of ꝛ to r, ſ to s, v to u, j to i, ʒ vs z, etc. seem generally similar, just typographic variants of a letter to be used interchangeably or with one form in the middle of a word and another at the end or beginning depending on the letter. (Disclaimer: I am not an expert on this topic.)