The question was asked at a recent user group meeting: Someone mentioned that publishing speeds increase significantly if you select “Keep default attributes” in each output format. Is there any reason that you know of to NOT do that? 

The field, FISHKEEPFIXEDATTRIBUTES, was added to improve publishing in the 10.0.1 release (LiveContent 2013sp1). In the user interface this is seen as a new checkbox, Keep default attributes, on the output format. This option, when checked, means that the attributes which have fixed defaults in DTD (#FIXED) are added to the XML file when they are exported during publishing. This results in the DTD not needing to be loaded again, since the needed attributes are in the XML document at publish time.

Since that time, SDL has also modified the all of the core publishing scripts to accommodate this FISHKEEPFIXEDATTRIBUTES field. It is recommended that FISHKEEPFIXEDATTRIBUTES be checked on for all output formats for all customers on version 10.0.1 or greater. The only caveat is that customers who have a customized the publish script will need to accommodate this change in their customized scripts. 

This behavior is enabled by checking Keep Default Values in the output format properties on the web client. If you have any issues after making this change, please contact customer support so that we can assist you.