Translation note for “On”

This string could use a translation note: https://translate.www.ads-software.com/projects/wp-plugins/robo-gallery/dev/nl-be/default/?filters%5Bstatus%5D=either&filters%5Boriginal_id%5D=4494107&filters%5Btranslation_id%5D=110452848

(See references for where the string is)

The reason why, is that it’s now confusing what “on” means. Does it mean “On/off” or “On something” or “On date X”. This minor improvement could help so many translators ??