An implicit address is specified by coding one expression. The expression can be relocatable or absolute. The assembler converts all implicit addresses into their relative-offset or base-displacement form before it assembles them into object code. The assembler converts implicit addresses into explicit base-displacement addresses only if a USING instruction has been specified, or for small absolute expressions, where the address is resolved without a USING. The USING instruction assigns both a base address, from which the assembler computes displacements, and a base register, which is assumed to contain the base address. The base register must be loaded with the correct base address at execution time. For more information, refer to Addressing.