- File Qualifiers:
  - File qualifiers are used to override the default interpretation of a Blue File. Usually they are used to override one of the values in the Blue File header.
  - File qualifiers are specified by appending them to the end of a file name. For example:

        X-Midas:   myfile.prm(<TAG>=<VAL>)
        NeXtMidas: myfile.prm{<TAG>=<VAL>}

    In the above example `<TAG>` is the name of the header value to override and `<VAL>` is the value to use. (Note that X-Midas uses parentheses while NeXtMidas uses braces.)
  - It is important to note that the syntax for qualifiers and the applicable `TAG=` names vary between the frameworks.
    - NeXtMidas choose a different syntax to allow qualifiers to be specified using a table (at the time X-Midas had no support for tables).
    - Both X-Midas and NeXtMidas give more details about the available `TAG=` names in the `HEADERMOD` explain file.
  - Multiple file qualifiers can be used at once. For example:

        X-Midas:   myfile.prm(<TAG1>=<VAL1>)(<TAG2>=<VAL2>)
        NeXtMidas: myfile.prm{<TAG1>=<VAL1>,<TAG2>=<VAL2>}
               or  myfile.prm{<TAG1>=<VAL1>}{<TAG2>=<VAL2>}

  - Both X-Midas and NeXtMidas allow the use of qualifiers that alter the interpretation/presentation of a file without directly overriding a value in the file header (a common example is `AUX=` which specifies the read/write AUX for the file).
    - Because of this, it is not uncommon to see qualifiers used with other types of file (especially in NeXtMidas).
  - (See Qualifiers in the User's Guide for details.)