Capital T is tesla, a unit of magnetic flux density.

very important comment /s

Old habits die hard. I still occasionally see some engineering veterans who use the capital letter "S" for seconds (and they would write "nS" instead of "ns" for nanoseconds) - even in chip datasheets. And when I was reading a textbook one day, I also noticed that the author, an expert with a life career at Bell Labs, just couldn't write MHz properly, and instead wrote "Mhz".

In their time, Siemens and Hertz had not even been added to the SI system yet, I imagine they would speak in terms of mhos and megacycles back then.

At least mhos and megacycles are unambiguous, unlike S or T.

Another commenter mentioned T is teslas, seems like the abbreviation for a ton depends on which ton you are talking about (wikipedia lists several and not all of them are mass/weight!).

From a conversion the article uses I believe they are using the metric ton (aka megagram) which abbreviates to the lower case t. The article you reference does not seem to ever abbreviate 'ton' and I suspect that may have been done intentionally to avoid running into this issue? Its what I would have done, anyway.

I don't think this impacts the readability of your comment I just thought it was a shame that the other comment didnt go all the way and attempt to describe correct useage.