An attribute can be set to hold a list of entity names. Entity names are required to be separated by white space.
<?xml version="1.0" standalone="yes"?> <!DOCTYPE rootelement [ <!ELEMENT rootelement (childelement1)> <!ELEMENT childelement (#PCDATA)> <!ATTLIST childelement sampleattribute ENTITIES #IMPLIED> <!ENTITY sampleentity1 SYSTEM "entity reference value 1"> <!ENTITY sampleentity2 SYSTEM "entity reference value 2"> ]> <rootelement> <childelement sampleattribute="sampleentity1 sampleentity2"> Child element. </childelement1> </rootelement>