EQUEL statements use BASIC variables to transfer data from a database or a form into the program and conversely. You must declare BASIC variables to EQUEL before using them in EQUEL statements. The preprocessor does not allow implicit variable declarations. For this reason, the "%" and "$" suffixes cannot be used with variable names. BASIC variables are declared to EQUEL by preceding the declaration with the ## mark. The declaration must be in a position syntactically correct for the BASIC language.

In general, EQUEL variables can be referred to in the program or subprogram in which they are declared. The scope of variables is discussed in detail in a later section.