The closest found was access:hazmat (only 15x in TagInfo), and was thinking of access:gpl=no and access:lpg=no, which few days ago was first time observed at a new supermarket's 'in-building' access route to roof and underground parking. Saw today a sign at a condominium's underground parking which in the UK is coded UK:822.8 UK:622.8 "no vehicles carrying explosives". Any pointers appreciated, all the more now the attention is peaked, had noticed a no-hazmat truck sign before a long tunnel like this https://taginfo.openstreetmap.org/keys/hazmat maybe hazmat:gpl and hazmat:lpg are the better combinations.

The closest found was access:hazmat (only 15x in TagInfo), and was thinking of access:gpl=no and access:lpg=no, which few days ago was first time observed at a new supermarket's 'in-building' access route to roof and underground parking. Saw today a sign at a condominium's underground parking which in the UK is coded UK:822.8 "no vehicles carrying explosives". Any pointers appreciated, all the more now the attention is peaked, had noticed a no-hazmat truck sign before a long tunnel like this https://taginfo.openstreetmap.org/keys/hazmat maybe hazmat:gpl and hazmat:lpg are the better combinations.