When the assembler processes your source statements for the first time, it assigns an absolute or relocatable value to every symbol that appears in the name field of an instruction. The assembler enters this value, which normally reflects the setting of the location counter, into the symbol table. It also enters the attributes associated with the data represented by the symbol. The values of the symbol and its attributes are available later when the assembler finds this symbol or attribute reference used as a term in an operand or expression. See "Symbol length attribute reference" and "Self-defining terms" in this chapter for more details. The three types of symbols recognized by the assembler are:

• Ordinary symbols
• Variable symbols
• Sequence symbols