A COM block is a set of one or more variables that may be shared (in "COMmon"), among one or more contexts. Each COM block is uniquely identified with a name (although one block is allowed to be nameless). COM block names are explained below.
The value of a COM variable is global in lifetime, however, the name of a COM variable is not global. To access COM variables, a context must include a COM statement which identifies the COM block and gives the names by which the variables will be known in that context. Thus, each context can give a different name to the same COM variable. COM variables are hidden from all contexts which do not include a COM statement accessing that COM block. See COM in the Reference Manual.
