- Main article: Names
The tag old_name=* is used for old / previous / historic name(s) for an element.
The tag should typically be combined with the current name=*.
For correct historic context of old names, the key may be suffixed with the date namespace. Example:
old_name:1921-1932=* (the name from 1921 until 1932)
If the start date of the name is the same as the start date of the feature/object, this can be clarified by instead using:
start_date=1921 (feature/object exists since 1921)old_name:-1932=* (the name from the beginning until 1932)
The key can also be combined with the language suffix old_name:xx=* with xx being the ISO code of the language. See: Multilingual names.
Example:
old_name:en=Constantinople or more specifically, old_name:en:330-1930=Constantinople
When combined, the language code comes before the date range:
old_name:ru:1925-1961=Сталинград
or
old_name:uk:1918-1926=Січеслав
It should be considered that historical objects of which there are no visible traces left do not belong into the OSM database.
was:name=* is also used, however in this discussion, most of the OSM community would prefer this key over the other.
Values
The general rules as for name=* apply.
Date ranges
The date ranges should follow the ISO 8601 date format.
When only ranges of years are specified (no month or other details), a single hyphen may be used, such as "old_name:1953-1990 = Ernst-Thälmann-Straße".
When full dates are specified or the simple notation is not sufficient, a double hyphen ("--") can separate the from and to date - e.g. "amenity:1965--1971-12-18 = school".