There are several good ideas in this thread all knife traders should be aware of.
The company I used to work for used e-mail filters. The filters flagged any incoming e-mail that used any number of (about) 700 words. The list fluctuated from time to time due to contract requirements. We were required to analyze these e-mails for security reasons. Point is, word and sentence scanning is a common security procedure in the corporate world.
I'm thinking the word "Damascus" got flagged because it's a city located in a volatile area of the planet. PayPal is like any other company. They don't want to deal with being investigated by government agencies tasked with tracking illicit financial transactions. I dont blame them.
I agree with others who recommend leaving the comments section blank, if possible. If you have to be specific due to circumstances (example: one seller selling 15 different knives. there is a need to organize in order to avoid confusion), used coded language. For instance, if you bought a knife made with M390 steel use the phrase: "M390 on BF." PayPal doesnt have a clue what that means, the other party does because theyre knife aficionados. Be discreet, everyone wins.
Avoid using key words like: knife, sword, blade, sharp.
NEVER use military sounding words: tactical, combat, bomb, attack, gun, firearm, intruder, home invasion, death. The probability of those transactions getting flagged is very high.