[3] [CITE@en[RFC 2244 - ACAP -- Application Configuration Access Protocol]], [TIME[2021-04-11T10:25:16.000Z]], [TIME[2021-04-21T09:50:14.643Z]] <https://tools.ietf.org/html/rfc2244#page-16>

[FIG(quote)[
[FIGCAPTION[
[1] [CITE@en[RFC 5231 - Sieve Email Filtering: Relational Extension]]
([TIME[2015-11-29 17:36:49 +09:00]] 版)
<https://tools.ietf.org/html/rfc5231#section-3>
]FIGCAPTION]

> The "i;ascii-numeric" comparator, as defined in '''['''RFC4790''']''', MUST be
>    supported for any implementation of this extension.  The comparator
>    "i;ascii-numeric" MUST support at least 32-bit unsigned integers.
>    Larger integers MAY be supported.  Note: the "i;ascii-numeric"
>    comparator does not support negative numbers.

]FIG]


[2] [CITE@en[RFC 5260 - Sieve Email Filtering: Date and Index Extensions]]
([TIME[2017-05-07 22:48:17 +09:00]])
<https://tools.ietf.org/html/rfc5260>