| Wade & Butcher — stamps and eras (the 1810s → the 20th century) | the 1810s → the beginning of the 20th century | 14 | W&B has no table of years of its own and never had one: the key is the wording of the stamp and dated specimens in private collections (Acier Fondu). |
| Country mark (lower bound, NOT a year) | the requirement applies from 1 March 1891 (Tariff Act of 1890, also known as the McKinley Tariff) | 2 | A country mark is only a LOWER BOUND (the item is no earlier than the introduction of the marking) and never a year. For W&B the mark ENGLAND on the t |
| Grind, spine, scales, etching — era markers of a straight razor | 1700s → mid-1900s | 16 | Shared layer for all straight razors: it does not date precisely, but it cuts off an era. All rows are printed wordings from a shop-page guide review |