If you would like additional ways to classify the issues your queries discover, the IR_TYPES table may be extended.

Create your own table to do this, called, say, IR_TYPE_CLASSES.

The key of this table is that of the IR_TYPES table; may as well call it IRType. It is a foreign key, referencing IR_TYPES. So your new table has a one-to-one relationship with IR_TYPES.

Add as many columns as you like to your new table, a column for each (orthogonal) sub-category by which you would like to classify reported issues. Boolean columns behave as a tag, toggling classification. Other kinds of columns, possibly containing foreign keys to control the vocabulary used, allow richer classification schemes.