[FIG(quote)[
[FIGCAPTION[
[1] [CITE[echo]]
([TIME[2024-06-23T03:02:51.000Z]])
<https://pubs.opengroup.org/onlinepubs/9699919799/utilities/echo.html#tag_20_37_04>
]FIGCAPTION]

> The [I[echo]] utility shall not recognize the "--" argument in the manner specified by Guideline 10 of [I[XBD Utility Syntax Guidelines]]; "--" shall be recognized as a string operand.
> 

]FIG]


[FIG(quote)[
[FIGCAPTION[
[2] [CITE@en[zsh: 17 Shell Builtin Commands]]
([TIME[2023-05-08T23:42:16.000Z]], [TIME[2024-06-23T03:10:18.544Z]])
<https://zsh.sourceforge.io/Doc/Release/Shell-Builtin-Commands.html>
]FIGCAPTION]

> All builtin commands other than ‘[CODE[echo]]’ and precommand modifiers, even those that have no options, can be given the argument ‘[CODE[--]]’ to terminate option processing. This indicates that the following words are non-option arguments, but is otherwise ignored. This is useful in cases where arguments to the command may begin with ‘[CODE[-]]’. For historical reasons, most builtin commands (including ‘[CODE[echo]]’) also recognize a single ‘[CODE[-]]’ in a separate word for this purpose; note that this is less standard and use of ‘[CODE[--]]’ is recommended.

]FIG]