It is possible to filter on attribute names matching the substr argument.
If an attribute-name is given, the description of that particular attribute will be displayed. If an object were given its value is displayed.
Attributes marked as internal will only be listed when the -i flag is used.
If the -show-description flag is used then description for the attribute is shown.
If the -only-connects flag is used then only attributes that represent DML connects are shown. This involves a heuristic check of the attribute description as generated by DML, so it might not be 100% accurate.