Assembly language is often described as the bridge between human logic and machine execution. However, without a disciplined approach to commenting, that bridge can quickly collapse into a labyrinth of cryptic mnemonics. Unlike high-level languages like Python or Java, where the code often describes its own intent through expressive variable names and abstractions, Assembly is stark and literal. A single instruction like mov eax, 1 tells you what the hardware is doing, but it says nothing about why it is doing it.

In professional systems programming, the semicolon (;) is the most recognized symbol for initiating a comment, but the art of Assembly documentation goes far beyond mere punctuation.

The Essential Syntax of Assembly Comments

The syntax for comments is determined by the specific assembler program being used—such as NASM, MASM, TASM, or GAS—rather than the CPU architecture itself.

Semicolon as the Universal Standard

In the majority of Intel-style assemblers (NASM, MASM, TASM) and many others, the semicolon ; signifies the start of a single-line comment. Everything from the semicolon to the end of that line is ignored by the assembler.