Extractor: hide Vs field only selection

Hello BW experts,
in datasource properties field in the R/3; what is the difference between the fields 'hide' vs 'field only'.
suggestions appreciated.


Hide field
You should set this indicator to exclude an extract structure field from the data transfer. As a result of your action, the field is no longer made available in BW when setting the transfer rules and generating the transfer structure.
if u dont want to see this this ..u set this field u cant see in the BW which is available in extrac structure
Field only known in exit
You can enhance data by extending the extract structure for a DataSource using fields in append structures.
The indicator Field only known in Exit is set for fields of an append structure. In other words, by default these fields are not passed onto the extractor from the field list and selection table.
Deselect the indicator Field Only Known in Exit to enable the Service API to pass on the append structure field to the extractor together with the fields of the delivered extract structures in the field list as well as in the selection table.
and also see this thread...
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