Why am I getting 403 forbidden when trying to post?

[NNadir]

7. Been there, done that over the years. Before clicking "preview..."

...I generally copy my longer elaborate posts into my word processor (MS Word).

I've been dinged by copy and paste text containing the mathematical symbol for "less than." It deletes all the text that follows which is lost.

It does allow for superscripts and subscripts but one needs to use "find and replace" functions in the word processor to make it work.

The DU editor does not like mathematical symbols, in particular Greek letters which produce the ? symbol. I think this was not the case years ago, but it is the case now. Recently I realized it will work with French accents and text. It does seem that this was not the case at another time.