Error message while saving data in Meta

Q: I am trying to save some new merchant data i Meta but get an error message. Why is that?

A: One reason could be that the comments field contains "illegal" characters that's violating our XSS (Cross-site Scripting) filter.

For instance, you're trying to save a comment that contains the following:

"29-04-2015 Capture blokkering opphevet, kunden har betalt /tbwa
28-04-2015 Capture blokeret grundet manglende betaling, chge
7/9 - 11 lagt till seb nyckel //toek
------------------------
17/1-2011 MAFA etrackno. 4693021
Internet Bas
Etabl: SEK 4990
Mån: SEK 690
Trans: SEK 3"

Upon saving you get this error message,

In this case the error message would be because you're using more than one dash in a row, which our XSS filter sees as an attack against the database.

There is more about Cross-site Scripting (XSS) on this Wiki page:
https://www.owasp.org/index.php/Cross-site_Scripting_(XSS)