I've already find this explanation of Microsoft about reserved words for Microsoft Access. and....oh surprise!!! "LONG" appears!!!
List of reserved words in Access 2002 and in later versions of Access
This article lists words and symbols that you should not use in field, object, and variable names in Microsoft Access 2002 and later versions of Access because they are "reserved words." Reserved words have a specific meaning to Access or to the Microsoft Jet database engine. If you use a reserved word or symbol, you may receive an error such as the following:
The wizard was unable to preview your report, possibly because a table needed by your report is exclusively locked.
If you use a reserved word, such as date, value, name, text, and year, in Access 2007, you may receive the following message:
The Name you supplied is a reserved word. Reserved words have a specific meaning to Microsoft Office Access or to the Microsoft Office Access database engine
For existing objects with names that contain reserved words, you can avoid errors by surrounding the object name with brackets ([ ]).