Fortran Wiki
maxcontin

what is maxcontin in fortran

You need to supply a bit more context. Most likely, you are referring to the -maxcontin switch on the NAG compiler, which lets you change the allowed number of continuation lines used in a single statement.

Or, someone wrote a function called maxcontin() that checks for the number of passes through a loop or routine and assumes if there are too many that the program should take an alternate action like stopping execution.

Or Max Contin had his name mangled, possibly because it contained non-ASCII characters.

So a little more information is needed to answer that.