You can use string tags as operands with the plus (+) arithmetic operator and with relational operators.
The + operator will join string operands. For example if the values of tag1 and tag2 are SOME and THING, the expression tag1+tag2 would return the value SOMETHING.
When using string tags with the relational operators, the initial character of the operand is evaluated first by capitalization and then by alphabetic order. Lower case letters are greater than upper case letters.