With the Data tab in the Symbol Details form or from Database Show Symbol Data, you can store a collection of data with each symbol.
To show this data on a diagram set the Display checkbox.
If a symbol has symbol data that has the same name as a field in the instances or objects for the class of the symbol then when building objects and instances, the value of the instance (or object) data is set to the symbol data value. The fields are also coloured in the Symbol Data tab of the Symbol Details form.
Another special object, SymdolData2, shows the data for that symbol and whether it is in the instance or object tables.
There is also Special Objects
PageData - this shows all the Symbol data for a diagram in a single list
PageData CrossTabTagCol and PageData CrossTabTagRow form tabulated lists from the data