For this particular case, we can guess this is an Evolution Working Group(EWG) issue from the Background section of the paper which says:
In Issaquah, EWG considered two alternative resolutions; this paper
offers wording for one of the two, and mentions the other only as an
acceptable alternative in case CWG uncovers fatal problems with EWG's
preferred resolution.
We can see from the latest C++ Standard Evolution Completed Issues List that the status of N3922
is WP
. For the Evolution Working Group the issue statues are defined on the active issues list we an see WP
stands for:
WP - (Working Paper) - The proposed resolution has not been accepted
as a Technical Corrigendum, but the full WG21/PL22.16 committee has
voted to apply the issue's resolution to the working paper.
and indeed issue 161 which is tracking this paper says:
Adopted into the working draft in Urbana, as N3922.
We can find the latest issues list for EWG and Core from the latest mailings and the latest mailings can be found off of the main WG21 site and going to the papers section and going to the latest date.
In the general case, the post meeting mailing Disposition column will tell you the status of a paper, for example from 2015 the post-Lenexa mailing shows the Disposition column for proposal N4508 A proposal to add shared_mutex (untimed) (Revision 4) says Adopted 2015-05
and we can confirm by looking at the latest draft standard which is also part of the mailing: N4527 Working Draft, Standard for Programming Language C++ and it indeed contain the new and modified wording. We can also usually find the latest draft standard by going to this answer from the question "Where do I find the current C or C++ standard documents?"
This may not always be helpful, in this case of N3922
was only listed in the post-Issaquah mailing and has an empty Disposition but was later adopted Urbana but there is no indication of this in the post-Urbana mailing.
What does "post-Issaquah" and "post-Urbana" mean?
The C++ standards meetings are usually referred to by the names of the places they took place. We can find a complete list on the isocpp.org site in the Upcoming Meetings, Past Meetings section. So for the example the May 2015 meeting took place in Lenexa, Kansas.
Before and after each meeting there is a mailing that lists all the documents relevant to that meeting and these are referred to as the pre and post meeting mailings, So for Lenexa we have the pre-Lenexa mailing and post-Lenexa mailing. The post meeting mailing will contain meeting minutes, updated proposals and potentially the Disposition of the proposal, the latest working draft of the standard, updated issues lists etc...