I didn't find this. Someone else in a Radiohead message board did, but I'll post it anyway:
In European folklore the magpie is associated with a number of superstitions[10] surrounding its reputation as an omen of ill fortune. This reputation may derive from the bird's well-known tendency to "steal" shiny objects or its aggressive behaviour toward favoured songbirds.
In Britain and Ireland, there are a number of superstitions regarding magpies[11]
A single magpie is associated with bad luck (see rhymes below)
One should make sure to greet magpies when they are encountered in order to either allay bad luck or encourage good luck as related to the number of birds and therefore their place in the Magpie poem. Common greetings include "Hello Mr Magpie" "How is your wife/where is your wife?", "Good Morning/Evening Sir" and other marks of respect.
Upon seeing a lone magpie one should repeat the words "I defy thee" seven times.
On seeing a lone magpie one should pinch the person they are walking with, if they are alone they are to pinch themselves. The custom in Devon is to spit three times to avert ill luck.
If a lone Magpie is seen, one should salute it to show you respect it. This formality can be forgone if the Magpie looks directly in your eyes, which shows it respects you.
In the 19th century book, A Guide to the Scientific Knowledge of Things Familiar, a proverb concerning magpies is recited: "A single magpie in spring, foul weather will bring". The book further explains that this superstition arises from the habits of pairs of magpies to forage together only when the weather is fine.
An old English folk tale states that when Jesus was crucified on the cross, all of the world's birds wept and sang to comfort him in his agony. The only exception was the magpie, and for this, it is forever cursed.
In Scotland, a Magpie near the window of the house foretells death.[12]
In Scottish folklore, in a story possibly related to the above, magpies were long reviled for allegedly carrying a drop of Satan's blood under their tongues.
I didn't find this. Someone else in a Radiohead message board did, but I'll post it anyway:
In European folklore the magpie is associated with a number of superstitions[10] surrounding its reputation as an omen of ill fortune. This reputation may derive from the bird's well-known tendency to "steal" shiny objects or its aggressive behaviour toward favoured songbirds.
In Britain and Ireland, there are a number of superstitions regarding magpies[11]
A single magpie is associated with bad luck (see rhymes below)
One should make sure to greet magpies when they are encountered in order to either allay bad luck or encourage good luck as related to the number of birds and therefore their place in the Magpie poem. Common greetings include "Hello Mr Magpie" "How is your wife/where is your wife?", "Good Morning/Evening Sir" and other marks of respect.
Upon seeing a lone magpie one should repeat the words "I defy thee" seven times.
On seeing a lone magpie one should pinch the person they are walking with, if they are alone they are to pinch themselves. The custom in Devon is to spit three times to avert ill luck.
If a lone Magpie is seen, one should salute it to show you respect it. This formality can be forgone if the Magpie looks directly in your eyes, which shows it respects you.
In the 19th century book, A Guide to the Scientific Knowledge of Things Familiar, a proverb concerning magpies is recited: "A single magpie in spring, foul weather will bring". The book further explains that this superstition arises from the habits of pairs of magpies to forage together only when the weather is fine.
An old English folk tale states that when Jesus was crucified on the cross, all of the world's birds wept and sang to comfort him in his agony. The only exception was the magpie, and for this, it is forever cursed.
In Scotland, a Magpie near the window of the house foretells death.[12]
In Scottish folklore, in a story possibly related to the above, magpies were long reviled for allegedly carrying a drop of Satan's blood under their tongues.
source: wikipedia