When there are ambiguities the full file name is appropriate. Single files in an image array can be designated by appending the index number of the image to the end of the name. The first image would be A.0. All fits data types are supported, although some functions do not handle unsigned char when it is not appropriate. Most functions also work on other data types not supported by FITS, such as unsigned 16 bit ints and unsigned 32 bit ints.
All operators handle blanks in float and double images, and for most of the other data types.
The notable exceptions are the ALU functions, such as addi, which only handled floats and double. All operators work on image arrays subject to the limit of 256 bands. Generate a Postscript File.