Recently I was recalling a Spanish verse that goes Qué descansada vida la del que huye del mundanal ruïdo... where ruido s correctly pronounced as rUI-dO but the poet needs three syllables to preserve the meter and so he forces rU-Ï-dO which is signalled in writing by using a dieresis. This is from the 16th century, when the preservation of meter was foremost in poetry. Nowadays, with free verse, people don't bother with meter and so they don't have a need to do violence to words with dieresis. Can the last politician to go out the revolving door please turn the lights off?