RFC 8011, "Internet Printing Protocol/1.1: Model and Semantics", January 2017

Errata ID: 6085
Status: Reported
Type: Technical
Publication Format(s) : TEXT
Reported By: Thomas Urban
Date Reported: 2020-04-10

Section 5.1.4 says:

The 'keyword' attribute syntax is a sequence of characters, of length
1 to 255, containing only the US-ASCII [RFC20] encoded values for
lowercase letters ("a"-"z"), digits ("0"-"9"), hyphen ("-"), dot
("."), and underscore ("_").  The first character MUST be a lowercase
letter.

It should say:

The 'keyword' attribute syntax is a sequence of characters, of length 
1 to 255, containing only the US-ASCII [RFC20] encoded values for 
uppercase letters ("A"-"Z"), lowercase letters ("a"-"z"), digits ("0"-"9"), 
hyphen ("-"), dot ("."), and underscore ("_"). The first character SHOULD be 
a lowercase letter, and all letters SHOULD be lowercase. 

Notes:

First, the "keyword" syntax is applicable to values of enumerations according to Section 5.1.5 stating

Each value has an associated 'keyword' name.

However, Section 5.4.15 is declaring some enum-type attribute with names per integer value using uppercase letters in violation of Section 5.1.4. Those names are commonly used all over the specification and thus it is rather common to assume those values are meant to be keyword-compliant names of given enumeration.

Second, Section 5.1.4 is stating

The first character MUST be a lowercase letter.

referring to "a"-"z" according to enumeration of accepted characters given right before that. In opposition to that statement 5.4.14 is declaring

The following standard 'keyword' values are defined in this document:

* '1.0' [..]
* '1.1' [..]

Neither of the two "keywords" start with a lowercase letter.

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