hard and fast
[ ˌhɑːd ən ˈfɑːst ]
• (of a rule or a distinction made) fixed and definitive.
• "there are no hard and fast rules about that"
Similar:
definite,
fixed,
set,
strict,
rigid,
binding,
stringent,
rigorous,
clear-cut,
cast-iron,
established,
inflexible,
immutable,
unalterable,
invariable,
unvarying,
unchangeable,
unchanging,
incontestable,
incontrovertible,
uncompromising,
