The format for coding a bit string constant is:

The value bbbbbbbb represents 8 bits that constitute a byte. Each bit must be 1 (test bit for 1), 0 (test bit for 0) or . (ignore bit). You can specify up to 256 groups of 8 bits. The total number of bits in the mask must be a multiple of 8. A bit constant can only be used for bit comparison tests (BI format and EQ or NE operator).