The | character is created by hitting shift-\. Sometimes it is displayed with a break, sometimes not. It can be hard to tell apart from Il1! in some fonts.

0b1110_0000 | 0b1000_0001 → 0b1110_0001

Logical OR is a logical carryless bitwise addition, 1s where either operand has a 1, otherwise 0.

0 | 0 → 0
0 | 1 → 1
1 | 0 → 1
1 | 1 → 1

Useful for combining bit masks. Don’t confuse this with ||. Given that you have a mask to describe the bit (all zeros, one one), to turn on a bit, use | mask .