[hhanesand]

Guessing those last two parameters are languages. I don't see the issue, but I commonly trim tracking strings off too.

[ta999999171]

For the layperson reading, for articles, this is usually anything after the ? in a URL.

[Johnny555]

That's not a good rule of thumb since often the unique identifier you're interested in is a query arg, so if you strip of everything after the ?, you're left with nothing. like the URL above, all you'll have left is:

https://webcache.googleusercontent.com/search

[userbinator]

Yes, there's no real general rule (see HN articles for instance) but "if I omit these parts of the URL, I get the same content" is usually a safe bet.