Escaping '?' in mask

I might have missed it in the doc but I was wondering what's the correct way to escape '?' in a mask.

If I do something like: 
cudaHashcat64.bin -a 3 -m 0 -1 ? myhash ?1 
or cudaHashcat64.bin -a 3 -m 0 -1 ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789? myhash ?1 

I don't get an error but it doesn't crack the hash, which for my testing was '?' and '??'

I tried using a hcmask like following:
hcmask = abcdefghijklmnopqrstuvwxyz0123456789?!@#$%^&*()_+-=,?1

cudaHashcat64.bin -a 3 -m 0 myhash myhcmask.hcmask

and I get:

Syntax error: abcdefghijklmnopqrstuvwxyz0123456789?!@#$%^&*()_+-=

but if I put a double ? it works it cracks the hash.
hcmask = abcdefghijklmnopqrstuvwxyz0123456789??!@#$%^&*()_+-=,?1

cudaHashcat64.bin -a 3 -m 0 myhash myhcmask.hcmask 


or in command line this works

cudaHashcat64.bin -a 3 -m 0 -1 ?? myhash ?1

Using a double ?? doesn't seem like a standard way of escaping I was expecting \? like for , or #