Spelling principle
Else clues• Rule broken by Heidi?
• Rule broken in leisure?
• Start of a rule broken by foreigners?
• Start of a rule that keeps you from spelling weirdly?
• Start of a rule with numerous exceptions
• Start of a school rule
• Start of a speller's shibboleth
• Start of a spelling mnemonic
• Start of a spelling rule
• Start of an English rule, and this puzzle's theme