I’m testing the 150-character limit on subject length. I want to see if I can enter more than 150 characters and save it.
I tried to enter 150 characters, by typing in 124567890, copying that, and then pasting it in 16 more times. The UI cropped my input, though, at 150 characters. I copied the contents of the field and paste them here:
123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
As we can see, that’s 150 characters, even though I pasted in more. So it looks like the limit is applied by the page’s code, at least, in this test case, entering text manually.