The format is as described in ICAO Doc 8126 section 5.5.2 bullet d):
In the indication of the geographical coordinates of a location: - the latitude should be given first; - symbols for degrees, minutes or seconds should be omitted; - two digits should always be used in expressing values of less than 10 degrees of latitude; and - three digits should always be used in expressing values of less than 100 degrees of longitude. For example, 050735N 0652542W means five degrees, seven minutes and thirty-five seconds North, sixty-five degrees, twenty-five minutes and forty-two seconds West.
What is typical in AIP pubblications is the additional part of decimal seconds, like `554718.23N`.
a string representation for longitude, i.e. 0114901W or 0114901.23W
decimal degress value
This format is used in AIP pubblications, for examples for runway threshold coordinates, stand positions, etc. This is used also in `ALL+` files from NM.
parse_lon_icao("0114901W")#>  -11.81694