An attribute left None is left out of the header, and means what leaving itout means: no Expires and no Max-Age is a session cookie, no Domain isthe origin host alone, no Path is the request's own directory.
The cookie a Set-Cookie field value states, or None when it states none —an empty field, or one whose first pair has no =.
Everything §5.2 says to ignore is ignored rather than refused: an attribute norevision defines, an Expires that is not a date, a Max-Age that is not anumber. A server sends what it sends, and a client that refused the headerwould lose the cookie over an attribute it does not even use.
The Set-Cookie field value this cookie is sent as.
Attributes come in RFC 6265 §4.1.1's order, which is the order a browser and alog reader expect. The octets a name, value, domain or path may not carry aredropped rather than escaped: what a reader gets back is then the text that wasset, and a \r\n smuggled into a value cannot open a header of its own.
An expires that is a time with no date aborts: a cookie cannot die at aclock reading, and a caller that built one has made a mistake rather than meta condition.
A cookie by name, with the defaults a server usually wants.
path defaults to /, so the cookie covers the whole site, and same_site toLax, which is what a browser assumes of a cookie that does not say — and whatstops a cross-site form post from carrying a session. Passing None for eitherleaves the attribute out.
Strict sends it only on a same-site request, Lax also on a top-levelnavigation, and Unrestricted sends it everywhere. Unrestricted is the wirevalue None, spelled differently here because None is the empty option; abrowser honours it only on a Secure cookie.
The pairs a Cookie field value carries, in the order they arrived.
A piece with no = is dropped rather than read as a name with no value, whichis what §5.4 leaves a server free to do and what every server does. Duplicatenames are kept: which one wins is the reader's decision, and [get] makes theone browsers make.