There is support for the OP's statement, in the case of Celsius at least [0], emphasis mine: > Because of this dual usage, one must not rely upon the unit name

There is support for the OP's statement, in the case of Celsius at least [0], emphasis mine: > Because of this dual usage, one must not rely upon the unit name or its symbol to denote that a quantity is a temperature interval; it must be unambiguous through context or explicit statement that the quantity is an interval. This is sometimes solved by using the symbol °C (pronounced "degrees Celsius") for a temperature, and C° (pronounced "Celsius degrees") for a temperature interval, although this usage is non-standard. Another way to express the same is "40 °C ± 3 K", which can be commonly found in literature. [0] https://en.wikipedia.org/wiki/Celsius#Temperatures_and_intervals https://en.wikipedia.org/wiki/Celsius#Temperatures_and_inter...