Here are the guidelines for naming a field:

- Field names cannot begin with a number
- Field names cannot include any spaces
- Field names cannot begin with an underscore
- Field names cannot have the same name as a SQL function or reserved word
- Field names cannot have same name as a 4D Command

To test a field name's validity, go to the Structure Editor and select a field. In the Inspector look at the bottom-most box labeled "SQL". If there is an error listed in that box then the field name needs to be changed. For example, see the following image:



In the image above, the '[Table_1]YEAR' field is selected in the strucuture editor window and the Inspector is visible. At the bottom of the Inspector window it displays "[!] SQL reserved word." - This is because the field selected (YEAR) is in fact the same name as a SQL function. To correct this, rename the field to a non-reserved word.