Guilty as charged. Yes, I use the word "transgendered" with respect to myself. And this it seems is Not The Done Thing in these here parts. Damn.
Still, it's always healthy to be challenged, and the post linked above goes beyond language pedantry or even the dreaded PC with the last question.
" Is this an activity for you, or is it part of your core identity?"
To which I have to answer: it's neither, instead it's simply descriptive. "Cross-dressing" is an activity I partake of from time to time. Here I have the luxury of presenting as female through my keyboard and believe me I'm a lot better at it here than in the real world, so my physical identity most of the time, whether I like it or not, is "Bloke". Yes, definitely bloke, it's an Estuary English thing. And my gender identity, nestling as it does somewhere between my ears and not between my legs, is "Female".
"I'm a bloke who's got a female brain and cross-dresses occasionally". might be accurate, but it's a bit of a mouthful and let's face it, it's going to raise more questions than it answers in the minds of the unfortunates to whom I deliver it here in the land of the pantomime dame.
Hence a descriptive word is required. "Transsexual" is medically accurate but still confusing. Thanks to our wonderful tabloid press it has slightly alarming associations in the minds of the Great British Public so I avoid it when talking to someone who isn't clued-up on the subject.
"Transgender" by comparison is nicely descriptive to anyone with the intelligence to deconstruct a compound word, but without any alarming tabloid overtones. And since it has to convey something of "You thought I was this but now you know I'm that", adding the "ed" suffix doesn't deny my dignity of being born any way but tells them something they knew about me has changed. "I am transgendered", simply descriptive.
Now, I'm an insomniac, so I'm knackered. Not knacker. I'm reminded of a personal piece of engineering language pedantry, don't get me on the subject of people who confuse accuracy and precision.