unspoken rules (usually ones that codify improper behaviors such as leveraging guanxi to get favorable treatment, or coercing employees for sexual favors)
Definitions (粵典–words.hk)
名詞
冇明文規定嘅規則 unwritten rule
Definitions (Wiktionary)
noun
unspoken rule; unwritten rule
verb, informal, neologism, slang
to apply the hidden rule that sexual favours are required for entry into an occupation or for career advancement