How to map label number in a note to a label name

I have the following issue opened in gitlab:

From the image, you can see that I added a label “Waiting for Acceptance” to this issue. When I get this data from the API it looks like this (I have replaced sensitive data with a string of x’s):

DB<45> x $temp_json = curl -s --header "PRIVATE-TOKEN: xxxxxxx" "http://xxxxxxxxxxx/api/v3/projects/24/issues/290/notes"
0 ‘[{“id”:3847,“body”:“Added ~31 label”,“attachment”:null,“author”:{“name”:“Adam Pfeiffer”,“username”:“apfeiffe”,“id”:8,“state”:“active”,“avatar_url”:“http://xxxxxxxxx/uploads/user/avatar/8/me.jpg",“web_url”:“http://xxxxxxxxx/u/apfeiffe”},“created_at”:“2016-01-25T22:56:11.114Z”,“system”:true,“upvote”:false,"downvote”:false}]’

In that data I see:
:“Added ~31 label”

which I think corresponds to ‘Added Waiting for Acceptance label’ as seen in the gui.

How can I map ~31 back to Waiting for Acceptance via the API? When I query the labels, I do not get the ~31 or 31 as part of the label data.