[Jamestown1630]

No, I’m not.

Maybe it’s my age, and style has changed, but I was taught in school to do it as I posted. (It stuck, perhaps, because my own name ends in ‘s’.)

https://www.thesaurus.com/e/grammar/whats-the-rule-for-doing-a-possessive-after-the-word-s/

https://grammarist.com/punctuation/apostrophes-with-names-ending-in-s/

(I’ve never heard prayer ended in church with ‘In Jesus-es name’.)

[HIDEK6]

My source is “The Elements of Style” by Strunk and White. This document was published in 1918 and has long served as the bible of journalistic style.

A person as old as you should be familiar with it.

You can google the book by that name. It is 51 pages long.

The rule, stated on page 11 reads, “Form the possessive singular of nouns by adding ‘s. Follow this rule whatever the final consonant.”

I find this rule to be clear and unambiguous.

The same rule can be found in the Merriam-Webster pamphlet covering the same subject matter.

[j.havenfarm]

Unfortunately I must agree that adding the “s” is the predominant form these days, though it is superfluous and awkward. The contrary, alas,
Minority, view is stated in countless places
https://www.hamilton.edu/academics/centers/writing/seven-sins-of-writing/4