If you signed up for an OSM account after May 2010 you may have noticed a check box with the label

“in addition to the above agreement, I consider my contributions to be in the Public Domain”.

Many years ago when the discussion started on the new licence for OSM data, one of the larger issues was if we should not adopt a very liberal (as in free) stance and use something close to a public domain distribution instead of the share-alike provisions we had in the existing CC by-SA licence. In the end, as you know, last year we switched to a licence with strong share-alike provisions, the ODbL, We did however add the “PD checkbox” in an attempt to span the gap between the two camps.

Unluckily what ticking the box would actually imply was, and continues to be, rather unclear; interpretations range from participating in an informal survey to actually giving permission to use the data on PD (or similar) terms. On top of that, at least for some time, there was a design issue with the specific page that potentially led to new contributors selecting the option inadvertently. Not to mention that the explanatory text changed multiple times in different locations.

To make a long story short: it is a mess.

In June MapBox asked the board for a list of the users that had checked the “PD checkbox” on sign up or later, see board minutes 2013-06-20. After some discussion and feedback from the LWG WG minutes 2013-06-25 the board decided to publish overall numbers on the one hand to give an answer to a not unreasonable information request and further to try and lay this issue at least partly to rest:

As outlined above, the numbers can at best be taken as an indication of sentiment.

If it wasn’t clear from the discussion of the quirky history of the checkbox and the legal uncertainty that surrounds it: this does not imply that an extract could be made from OSM data that contains a substantial amount of “PD” data. Outside of the already mentioned issues, edits from accounts with this flag set are intermingled with edits of those that don’t have it set, and as the statement from the licence working group says: there is no guarantee that a user actually only contributed and continues to only contribute data from sources that are compatible with a PD distribution.

To conclude: while a significant minority of our contributors would prefer a less restrictive licence, and this will not be ignored in future discussions, we are currently obliged to operate within the spirit and letter of our current licence.