Perks on an MP include free snuff The unusual perk was disclosed in a background briefing, provided to MPs "in support of their parliamentary duties" last week. The document also details how MPs must handle relations with each other inside and outside Parliament and the rules which must be observed during debates. Commons Speakers have banned the use of words deemed "unparliamentary," which have included "blackguard," "coward," "guttersnipe," "rat," "stoolpigeon" and "traitor" Certain activities are also deemed to be out of order during debates, such as carrying briefcases and reading newspapers, magazines or letters. Mobile phones and other electronic devices must be set to silent mode in the Commons. Apart from the occasional sip of water "to ease the voice," eating and drinking are not permitted. The document noted that this was "in contrast to what must have happened in previous centuries, when visitors observed Members sucking oranges and cracking nuts." At the end of each sitting, when the House "rises," two doorkeepers in the Commons simultaneously shout "Who goes home?" This is believed to date back to the time when members would join together in bands to cross the "dangerous unlit fields" between Westminster and the City of London, or to share a ferryboat homewards on the Thames. Contrary to popular belief, dogs are "not generally allowed" in the Commons, unless they are guide dogs. There is "no truth" in the claims that King Charles Spaniels are exempt from the ban, the paper warned. Parliamentary dress codes have changed substantially over the centuries. Tall hats were once essential and would often be left on a seat in order to reserve a member's place, on the grounds that the wearer was certain to return because he could not contemplate leaving without it. The custom led some MPs to bring two hats to Parliament with them in order to ensure that they could reserve a seat without needing to remain in the Palace. Men were required to remove their hats before speaking during a debate and are still not permitted to address the House whilst wearing a hat, although women are exempt from this rule. During the daily procession of the Commons Speaker through the Palace of Westminster to the chamber, a police officer will shout "Hats off strangers" as an instruction to members of the public to remove their headwear.