Syntax sql is not correct
If in syntax SQL use the value \ in ’ ’ then all further text displayed as STRING.
sMaskChar varchar2(1) := ’ \ '; (without spaces)
This appears to be a bug in Scintilla that has been there since the dawn of time. Coincidentally, this was patched a month ago. The bad news is that it can take a long time before NPP gets a new Scintilla engine. If it’s really vexing you, you could install the Poor Man’s T-Sql Formatter plugin. I think that comes with a custom language definition that doesn’t suffer from the same bug. It does some nifty automatic formatting for you too.