Multiple real number options accept base ten numbers with optional fractional components. Additionally, leading zeros are ignored and numbers can be specified in scientific notation using 'e' syntax. Multiple numbers are delimited using , or ; or : with duplicates ignored.

The accepted range and interpretation depends on the context of the option.

Option set
--switch=0
--switch=1,2,3
--switch=1E3:3.0

The option may also be set an empty set by not specifying a value.

Option set to empty
--switch
--switch=