निवेशार्धं हस्तिनखम् ॥ कZ_०२.३.२९ ॥
niveśārdhaṃ hastinakham
The (gate/entry) installation should include an ‘elephant-nail’ (hastinakha) to the extent of half the installation measure—i.e., a protruding spike/ironwork sized proportionately for anti-elephant defense.
It enforces predictable, inspectable compliance—officials can audit whether defensive fittings meet the mandated standard.