an example of the need for simpler rules: the apostrophe

D: I have the seventh sense. I see dead punctuation everywhere. Nobody else can see it. And the punctuation doesn't know it's dead. <:

I never quite figured out why most folks find the apostrophe so difficult. I mastered it in primary school. Yet many of my liberal arts grad friends have yet to figure it out.

Punctuation is not set in stone. What is considered appropriate usage has varied by time and place. There is still disputes even among the most learned of us.
Having said that, consider the following passage:

• My sister's friend's investments (the investments belonging to a friend of my sister)
• My sister's friends' investments (the investments belonging to several friends of my sister)
• My sisters' friend's investments (the investments belonging to a friend of several of my sisters)
• My sisters' friends' investments (the investments belonging to several friends of several of my sisters)

I will review the most common errors.

1) "dog's" This could mean the possessive "the dog's bone" but no plural.
2) "it's" This can only mean a short form of "it is". Perhaps "'tis" was clearer.
I think I know why people screw that up. My, your, his, its. BUT Henry's, Mary's ...
They know sometimes there is an apostrophe. The English system is clear as mud.

Aside - the US rule suggests using an apostrophe for the plural of an acronym. For example, RRSP's. In Canada we don't ( I corrected the Royal Bank for the GIC's).
I much prefer our system. It allows more information. For example, how does one clearly indicate the possessive of GIC? It resembles plural with the US rule.

D: what to do?
Well ... if I ever get around to completing Hioxian, I plan to allow an optional overt indicator of what role a piece of punctuation is playing.
I read "Eats, Shoots & Leaves: The Zero Tolerance Approach to Punctuation ".
It was a fun read. Each punctuation symbol typically had only a handful of uses. This allows me to use Hioxian with a "subset usage indicator" mark on each symbol.