I couldn't see any football players wearing caps while playing international matches, but I could see some of them wearing large headbands.
What's the rules for Football say about this?
If the football players are not allowed to wear cap means, what is the reason for allowing large head-bands but not head caps?
As per FIFA's "Equipment Regulations", Section 22, only the goalkeeper is permitted to wear a cap.
22.1 All goalkeepers may, irrespective of the prevailing conditions, wear a goalkeeper cap of any Colour. The goalkeeper cap must be produced by the Manufacturer of a Playing Equipment item. The goalkeepers of the same team may wear different goalkeeper caps.
The rule regarding caps was brought in to afford goalkeepers better visibility in sunny conditions, with the cap shading the eyes from the glare of the sun. The rule includes the line "irrespective of the prevailing conditions" so that goalkeepers can also where a cap even if there is no sun. Some goalkeepers will wear a cap in the rain so that their vision is not impaired by rainwater in their eyes.
Regarding headbands (and wristbands), section 24 states:
24.2 The Players may wear a headband or wristbands. Neither the name, or any abbreviation thereof, nor the number of a Player may be displayed on a headband or wristband.
Headbands and wristbands reduce the problem of sweat and rain and remain a personal choice as to whether the player wears them.
On p. 90 of the document @Ste linked to, we read
2.3 Goalkeeper cap and further caps [My emphasis.]
This seems to indicate that caps may be worn by other players as well.
Law 4 stipulates
A player may use equipment other than the basic equipment provided that its sole purpose is to protect him physically and it poses no danger to him or any other player. [My emphasis.]
and
Modern protective equipment such as headgear, facemasks and knee and arm protectors made of soft, lightweight padded material are not considered dangerous and are therefore permitted.
My interpretation would be that a non-goalkeeper is allowed to wear a hat or cap, but that such a hat may not be peaked, because that would serve a purpose beyond protection.
Although headgear is allowed to be worn, it is not advised for anyone other than the goalkeeper. This could be because:
Goalkeepers can wear caps. Field players can wear beanies. I often wear a cycling-style cap with a small brim to help when I'm looking into the sun playing keeper.
Lev Yashin, who is kind of the Russian goalkeeper version of Pele, often wore a hat:
He often played wearing a cloth cap of burnt-brick colour.
From The Laws of the Game, Law 4:
- Other equipment
Non-dangerous protective equipment, for example headgear, facemasks and knee and arm protectors made of soft, lightweight padded material is permitted as are goalkeepers’ caps and sports spectacles.
Head Covers
Where head covers (excluding goalkeepers' caps) are worn, they must:
- be black or the same main colour as the shirt (provided that the players of the same team wear the same colour)
- be in keeping with the professional appearance of the player’s equipment
- not be attached to the shirt
- not be dangerous to the player wearing it or any other player (e.g. opening/closing mechanism around neck)
- not have any part(s) extending out from the surface (protruding elements)
