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}.