Subsection (2) applies where—
a landlord (having given a contract-holder a notice under section 173) has made a possession claim on the ground in section 178, and
the court has refused to make an order for possession because it considered the claim to be a retaliatory claim (see section 217).
The landlord may not give another notice under section 173 to the contract-holder before the end of the period of six months starting with the day on which the court refused to make an order for possession.
This section is a fundamental provision which is incorporated as a term of all periodic standard contracts which incorporate section 173 as a term of the contract.