integer function fddx_mod(alias, value, title, old_tag)
After opening a file for input with "fddx_mod" the input buffer Dictionary will be left open for scanning. The open process will look for "alias" for the Dictionary (or usp, segy or su binary on input), "alias_data" for overriding the binary, and "alias_format" for overriding the format. The input parameter, "value", is the default value used for a fallback in cases where "alias" is not specified by the user. The input parameter, "title", should be a brief one line description of the application program to append information onto an existing dataset; otherwise it just uses "old_tag" from which to create a new one. It will return a binary tag associated with the internal binary upon successful opening, a value of -2 if the dataset is not specified and no default value is given, otherwise a value of -1 to signify an open failure.