| System | Period | Rows | What it dates |
|---|---|---|---|
| Rolls Razor — the 2-digit year on the blade spine | the very early 1900s → 1963 (production of Rolls Razor Ltd.) | 3 | This is the only working Rolls dating key: the name and the year are on the BLADE. If there is no 2-digit year, the blade is a replacement and no date |
| Rolls Razor — models, sets and cases (the 1900s → 1963) | the very early 1900s → 1963 | 6 | The model is dated by packaging and set; only the blade gives an exact year (see rolls-blade-year). Rolls cases survive in large numbers, so a set wit |