For example, although adding a possessive suffix 's to the nane "Jordan" would result in "Jordan's," adding it to "James" could result in "James'". There's an apostrophe written at the end, but it's pronounced the same way as "James."
I said it's not universal because I still know people who would say "James's" (with an extra syllable at the end) in everyday speech anyway. I don't know to what extent this varies by dialect.
It's also elided when a plural already ends in s (and I think this is universal, but I haven't looked it up). For example, "the doctor's computer" (the computer of one doctor) sounds the same as "the doctors' computers" (the computers owned by the doctors). The apostrophe is written on the other side of the s, but it also sounds the same. Note that not all plurals end in s, e.g. man/men, woman/women, goose/geese, etc., and in these cases you still add the s, e.g. "the geese's beaks".