O in this context is UK English for zero, for example:
012 smile => zero one two smile (US) o'one two smile (UK)

in the US, for some unexplained reason,
when reading out numbers
(telephone, credit card, bankaccount, social security, etc.),
there is a tendency to say "oh" insted of "zero".
I have no idea what the origin of this practice is.

so a telephone number with the following digits:
(806) 213-0067
can be read out as:
eight-oh-six-two-one-three-oh-oh-six-seven
or as
eight-zero-six-two-one-three-zero-zero-six-seven

eytan