libphonenumber/resources/metadata/255/altformats.csv

1	Format	Parent Format	Comment
2	XX XXX XXXX	mobile_3/3/3	A standard for mobile formatting is not well established and using two digits for the first group is very common.
3	XX XXXX XXX	mobile_3/3/3	A standard for mobile formatting is not well established and using two digits for the first group is very common.