My 'U' Style Guide
Back in 2012 I decided to begin spelling 'you' as 'U'. My dear friend Tasshin Fogleman has written about his own adoption of this practice.
I find that doing so creates a beautiful symmetry in the English language between 'U' and 'I', promoting both pronouns to capitalized single letter words. Happily, the pronunciations of both letters exactly line up with the pronunciations of the entire words.
This decision comes with a host of other questions about style. I'll share some of the choices I've made, and why.
Possessives: your vs Ur vs ur
Regarding possessives, I continue to use 'your'. I find 'Ur' or 'ur' both hard to parse when reading. Unlike 'U' that difficulty doesn't boil down to mere unfamiliarity. "Your" actually sounds phonetically close to 'your', and not 'ur'.
I associate 'ur' with mobile texting dialect and its use feels un-deliberate to me. When making the linguistic leap of using 'U' I prefer to convey an impression of grammatical competence elsewhere, to enhance the deliberate feeling of 'U'. Lower casing 'U' rather defeats the purpose anyway.
When I see 'Ur' I think of the ancient city. In theory I like this better because it preserves capitalization, in practice I don't enjoy how it reads. It has no symmetry with 'my', 'mine', which we wouldn't render as 'mI', 'mIne' or such.
Contractions
I will write, "U'll" for "U will", and "U'd" for "U would", etc. These feel symmetrical with "I'll" and "I'd".
U're vs you're
I generally sidestep this one. It has more arguments in favor of "U're" but all the same drawbacks as "ur" or "Ur", phonetically speaking. Since I practice E-Prime, I consider it poor form to make "is" statements, especially about U, so I avoid this construction in either form.