Field Alias
In principal there are three options where to define field aliases:
•in the geodatabase
•in the ArcMap MXD document
•in the WebOffice 10.9 R4 project configuration
In practice, whenever it is possible, specify field aliases in the geodatabase. This way, you can immediately use these aliases in every ArcMap document and WebOffice 10.9 R4 project. Aliases are only defined once in a centralized location. Redundancies can be avoided.
Only if this is not possible, then define aliases in the ArcMap document itself. Anyway there is a significant tradeoff when defining aliases in the ArcMap document: You must do this again in every map document you use. Therefore there is considerable potential for generating a lot of redundant alias definitions which may cause a lot of additional time to maintain.
Try to avoid defining field aliases in the WebOffice 10.9 R4 project configuration unless, e.g. you want to provide multilingual projects, since WebOffice 10.9 R4 is capable of using geodatabase or ArcMap field aliases. Therefore, if you use geodatabase or ArcMap field alias definitions, you do not need to provide any field alias configuration in the WebOffice 10.9 R4 project at all. This makes creation and maintenance of your WebOffice 10.9 R4 projects easier and more efficient.
ArcMap layer properties - fields