Phone number searching tips

I tried putting in phone numbers as

800-555-1212

and as

800.555.1212

but when I went to search for them they would not show up...

I tried

800x555x1212

and

800m555m1212

both worked

my preference if for the

800m555m1212

If you are using a "smart phone" with just a phone keypad m is easier than x because if you press 1 time on 6 you get m

to get x you have to press 9 twice.