[ietf-dkim] Clarification on z=

[Eric Allman]

OK, enclosed is my proposed re-wording for z=.

eric

Copied header fields (plain-text, but see description; OPTIONAL, 
default is null). A vertical-bar-separated list of selected header 
fields present when the message was signed, including both the field 
name and value. It is not required to include all header fields 
present at the time of signing. This field need not contain the same 
header fields listed in the "h=" tag.  The syntax used resembles 
Quoted-Printable [RFC2045]: any character MAY be encoded as an "=" 
followed by two hexadecimal digits from the alphabet 
"0123456789ABCDEF" (no lower case characters permitted) representing 
the internal value of that character.  All control characters (those 
with values < %x20), eight-bit characters (values > %x7F), and the 
characters DEL (%x7F), SPACE (%x20), vertical bar ("|", %x7C), colon 
(":", %x3A), and semicolon (";", %x3B) MUST be encoded in both the 
header field name and the header field value.  Note that all white 
space, including CR and LF characters, must be encoded.  After 
encoding, SWSP MAY be added at arbitrary locations in order to avoid 
excessively long lines; such white space is NOT part of the value of 
the header field, and MUST be removed before decoding.