Category:Articles with unknown NFPA 704 code

This category is not shown on its member pages unless the appropriate user preference (Appearance → Show hidden categories) is set.

Administrators: Please do not delete this category as empty! This category may be empty occasionally or even most of the time.

Category should be empty.

Unknown NFPA 704 codes used. Articles are sorted by F, H, R, or S depending on the unknown code.

When there are multiple unknown codes, the article will be sorted under any one letter. So a page with an erroneous "F=7" code may be under "R" when that has an error too (like "R=5"). All error articles are in this category -- somewhere.

See {{NFPA 704 diamond}} for documentation. Note that code "S" (Special) is used, not "O" (Other).