You can have as many keyword groups as you want. E.g. one group can be standard keywords and another group data types.
Enter a name to the keyword group and then add keywords to that group.
You can also use regular expressions to identify a keyword. You can only have one expression per keyword group. The group name must start with #.
If the option to only allow syntax highlighting inside blocks is set to "true" - you can still highlight keywords in groups that begin with _ or #_ (regular expression).