Names

Names are used in Fortran 90 to denote entities such as variables, procedures, derived types, named constants, and common blocks. A name must start with a letter and consists thereafter of any combination of letters, digits, and underscore (_) characters.

As an extension in HP Fortran 90, the dollar sign may also be used in a name, but not as the first character.

Standard Fortran 90 allows a maximum length of 31 characters in a name; in HP Fortran 90 this limit is extended to 255 characters, and all are significant— that is, two names that differ only in their 255th character are treated as distinct. However, names and keywords are case insensitive; thus Title$23_Name and TITLE$23_NAME are the same name.