Demonstrate the symbol used in data dictionary

A number of the symbols used in data dictionary are as following:

X= [a/b]                                   x comprises either data element a or b

 X=a                                        x comprises an optional data element a

X=a+b                                     x comprises data element a andb.

X=y{a}z                                 x comprises some occurrences of data elements a which are between y and z.

|                                               Separator

 **                                           Comments

 @                                           Identifier

 ( )                                            Options