Louis Davidson explains how bit operations work in T-SQL:
I expect that 99% of the people reading this looks at this probably would expect there to be a status table that contained the values of status. Seeing that this is a base 2 number, you may be in that 1% that thinks this might be a bitmask. but unless you have and eidetic memory, you probably don’t know what all of the bits mean.
A bitmask is a type of denormalization of values where instead of having a set of columns that have on or off values (no Null values), you encode it like:
Bitmasks make me break out the angry nun ruler. You can almost guarantee you’re doing something wrong if you design a bitmask as a column in a table.