Original text:
named field as defined in HTTP.  The field value MUST be taken from the named header field of the target message unless this behavior is overridden by additional parameters and rules, such as the "req" and <del> "tr" flags, below. </del>  Unless overridden by additional parameters and rules, HTTP field values MUST be combined into a single value as defined in HTTP to

Reviewer comments:
Addresses encodings of signature component values for query parameters and field values.
: This seems to be inconsistent with Section 2.2.8 ("Query Parameters"), which could create non-ASCII component values.
FWIW, a query parameter (after application of URL) could contain CR, LF and other control characters.
So we likely need to serialize information extracted from query parameters using some kind of encoding; maybe an SF Byte Sequence.
This is tricky -- originally the query parameters were kept in percent-encoded form but from WG discussion we changed that to just use the unencoded value instead since several percent-encoded forms could be used. However it does look like the unencoded form could end up with problematic values here, so maybe we need to go back to that. I'd rather us use an encoding native to the value rather than inventing something to put on top of it, even trying to re-use the flag we've already got defined for headers.
And we did that because to extract query parameter values, we need a query parser, and that is defined the way it is. I believe that decision was good, we now just need to figure out out to transform the extracted values so that they can be used in the signature base. (And, FWIW, at the end we also should have an example for a case like that in the spec).
In 2.2.8, it might be good to mention that the referenced algorithm only supports query parameters using (percent-escaped) UTF-8 encoding (this came as a surprise to me because I assumed it works the same as the algorithm used for forms decoding).
in 2.1.3: What if the field value contains non-ASCII characters (from obs-text)? Of course that could be considered an error, but I believe the intention is to be able to represent anything here. So the text should refer to the field value as byte sequence, in which case the encoding step would not be needed.
This text was added in response to a comment about needing to know which encoding to put into the byte sequence input, and the commenter suggested ASCII as the base for it. If field values have a well-defined byte sequence that isn't ASCII characters only, then we should refer to whatever that is from the HTTP docs.
Well, field values in HTTP can be anything. It's obsolete, it's deprecated, but that's what it is. So we need to deal with it one way or another. I could live with UTF-8, and a note that if the octet sequence does not decode as UTF-8, you can't sign it.
NAME - yes, you can merge and close issues as you wish, you are the editor. But by all means do not submit a new draft until the changes have been reviewed by those who opened the issue. (cc chairs NAME NAME )
As far as I can tell, the changes require percent-encoding only for non-ASCII values. That is, the character U+0080 would get the same encoding as a verbatim "%80" in a field value. I believe this is a problem.
This issue has been addressed. There is no percent encoding needed in this section since the value is taken directly from the bytes of the field in a binary-wrapped representation, and the bytes are encoded using the base64 serialization of a Byte Sequence from Structured Fields:
I'm talking about the simple case, not the one where Byte Sequence encoding is used (yes, the issue title doesn't match anymore).
Ok, opened new issue URL

Revised text:
named field as defined in HTTP.  The field value MUST be taken from the named header field of the target message unless this behavior is overridden by additional parameters and rules, such as the "req" and  <ins> "tr" flags, below.  For most fields, the field value is an ASCII string as recommended by HTTP, and the component value is exactly that string.  Other encodings could exist in some implementations, and any characters outside the ASCII range MUST be encoded using the percent-encoding mechanism defined in URI. </ins> Unless overridden by additional parameters and rules, HTTP field values MUST be combined into a single value as defined in HTTP to