[4]: 8.2.1 Some languages use the idea of l-values and r-values, deriving from the typical mode of evaluation on the left and right-hand side of an assignment statement.
In many languages, notably the C family, l-values have storage addresses that are programmatically accessible to the running program (e.g., via some address-of operator like "&" in C/C++), meaning that they are variables or de-referenced references to a certain memory location.
An immediate value is stored as part of the instruction which employs it, usually to load into, add to, or subtract from, a register.
Processors often support more than one size of immediate data, e.g. 8 or 16 bit, employing a unique opcode and mnemonic for each instruction variant.
If a programmer supplies a data value that will not fit, the assembler issues an "Out of range" error message.
Most assemblers allow an immediate value to be expressed as ASCII, decimal, hexadecimal, octal, or binary data.
The byte order of strings may differ between processors, depending on the assembler and computer architecture.