@oldladyplays

(It's not a loan word change: it's that in Polish there's no way to spell hard s followed by I, and yet loanwords are like that.)

"rz" is an edge case. I can't recall more that two extended word families that use it as an r followed by a z, so unless a friend of yours is called something like Zmarzlik it won't matter for names.

I've had significant difficulty with explaining the differences between ć, ś, c, s, cz, sz, ż even in person so I think that a description from a POV of someone who didn't learn them in childhood is a very useful thing.