"MW" stands for Medium Wave(band), only on European model
"TA" stands for Traffic Advisory, only on European model
"P1" stands for Preset 1, on all models
You need to set up your radio so that it does not assume a random default when first turned on. You can have a total of 15 preset stations on FM band in Europe, (or up to 15 AM, FM and XM each on USA and Canadian models).