This appears to be a generic term for miscellaneous marks that did not fit one of the other categories, with descriptions including "Brass centre mark", "Brass ferrule","Pipe Nail" and "Arrow scratch on roof". "Brass centre mark" is perhaps synonymous with "roof bolt".
3 of these marks have been recorded as destroyed.
- Grimethorpe Colliery Baths Twr Brass Ferrule Mark (two marks)
- Hemmingfield (but apparently never installed)
5 are deemed inaccessible:
- British Library Brass Centre Mark
- Otley Church Brass Centre Mark
- Wetherby Church Tower Brass Centre Mark
- Coseley Church Tower Auxiliary Mark
- Wishaw House
1 has not been found:
and 1 uncertain id/possibly missing: