Recently there has been a lot of this, especially involving heavy copy/paste from the Cirrus Jet marketing material.
It isn’t “really completely totally” against our Guidelines if the poster contributes to EuroGA generally, but it devalues the posting in question because anybody with an IQ of > 10 will right away regard that post as advertising.
Sometimes it is appropriate and relevant to quote text from a marketing website (or from a regulatory website, etc) and then the correct way is to put it in italics so it is obvious to all it has been copied/pasted from somewhere.
There is more than one way to do italics (see Posting Tips) but when I do this I use
blah blah blah blah blah blah blah blah blah
blah blah blah blah blah blah blah blah blah
blah blah blah blah blah blah blah blah blah
Thank you.