text: https://wiki.openstreetmap.org/wiki/Barriers is an informational page only, and the passage in question was inserted by user Oligo without discussion. The access keys are actually defined on https://wiki.openstreetmap.org/wiki/Key:access which explicitly states: "Access values describe legal permissions/restrictions." That leaves no doubt, does it? However, there have been various mistakes in the translations of this page, e.g. the german translation had an incorrect definition "nicht erlaubt oder nicht möglich" (not permitted or not possible) for the "no" value from 2008 till 2015, when it was finally corrected to "nicht erlaubt" (not permitted) as in the English page. Mistakes like this, particularly when they stay in the Wiki for so long, spread like viruses, and that's why many mappers and even validators believe that lift gates must be tagged with foot=yes etc. :-(