By Frances Harrison
BBC Religious affairs correspondent
Iranian newspapers have printed a list of moral vices that the police are targeting, including wearing make-up and hats instead of headscarves.
The fashion crackdown is more serious than in previous years
The police say they will also suppress "decadent" films, drugs and alcohol.
This year has seen one of the most ferocious crackdowns on un-Islamic behaviour and improper Islamic dress by the authorities for at least a decade.
But it has now emerged the current campaign has the overt backing of the Supreme Leader, Ayatollah Ali Khamenei.
The police are warning they will deal seriously with any women who dare to wear short trousers, skimpy overcoats or skirts that are revealingly transparent or have slits in them.
Wearing boots instead of full length trousers will not be tolerated, nor will hats instead of headscarves.
Indeed, the police stipulate that small headscarves are out - the scarf must cover a woman's head and neck completely.
The police say they will also clamp down on "decadent" films, drugs, alcohol, extortion and general thuggish behaviour, but it is issues of dress that are given most prominence.
In the last six months, tens of thousands of women have been warned or arrested because of their clothes.
IRANIAN MORAL VICES
Terrorising people by quarrelling and feuding in public
Women failing to cover up in a suitable way, such as wearing short trousers revealing the leg, hats instead of scarves, small and skinny scarves that do not cover up the head, and make-up that is unconventional and violates public morality
Wearing decadent Western clothes and displaying signs and insignia of deviant groups
Procuring decadent films
Procuring drugs and alcohol
Source: E'temad newspaper
During the reformist period, Islamic dress restrictions eased dramatically in Iran, with women wearing bright colours, following Western fashions, and pushing the limits in an attempt to express their individuality.
Some sported strappy, high-heeled sandals with tight three-quarter length trousers, skin-hugging coats at least a size too small, a headscarf perched on the back of their heavily highlighted hair, topped off with large diamond-encrusted sunglasses and matching designer handbag.
But the latest police action has put an end to that kind of dress.
Last week, Ayatollah Khamenei urged the police to keep up their crackdown on social vices, clearly lending his weight to a campaign that has proved controversial.