shift left (or right) logical = S = shitogram

shim n.

A small piece of data inserted in order to achieve a desired memory alignment or other addressing property. For example, the PDP-11 Unix linker, in split I&D (instructions and data) mode, inserts a two-byte shim at location 0 in data space so that no data object will have an address of 0 (and be confused with the C null pointer). See also loose bytes.

shift left (or right) logical = S = shitogram