Any priority rule has effect subject to the general anti-abuse rule (despite the terms of the priority rule).
A "priority rule" means a rule (however expressed) to the effect that particular provisions have effect to the exclusion of, or otherwise in priority to, anything else.
Examples of priority rules are—
the rule in section 464, 699 or 906 of CTA 2009 (priority of loan relationships rules, derivative contracts rules and intangible fixed assets rules for corporation tax purposes), and
the rule in section 6(1) of TIOPA 2010 (effect to be given to double taxation arrangements despite anything in any enactment).