Hi @KasimirNepomuk , the “double escaping” is generally needed in KNIME (and some other languages) when the regex is in a literal string within a script. This is because KNIME first has to interpret the string, which can also contain escapes. So in the first level of parsing, the single `\` is treated as an escape within the script, and this is before it is passed to the regex engine, so what gets passed to regex has had a single escape already stripped.