Out of the box artefacts that read this property. Append the path to your instance URL to open the record and see how the value is used.
ACL script: kb_social_qa_answer
When a question has no knowledge base, this setting supplies the fallback knowledge base used to check whether the user may create an answer; if it matches the community knowledge base, creation is denied. Admins can change which knowledge base is checked, and the code specifies no default value.
/sys_security_acl.do?sys_id=521aa073c31331006f333b0ac3d3aec1
ACL script: kb_social_qa_answer.*
When a question has no knowledge base, the ACL uses this property to choose which knowledge base’s answer-creation permissions to check; otherwise, it checks the question’s knowledge base. The configured value can therefore affect whether users may create an answer, while the community knowledge base is denied; no default value is supplied in the code.
/sys_security_acl.do?sys_id=97dd8623472102007f47563dbb9a71c5
ACL script: kb_social_qa_question
When the question has no knowledge base set, the access check reads this property and uses its value to decide whether the user can create a question in that knowledge base; the configured community knowledge base is denied. No fallback default is supplied in the code.
/sys_security_acl.do?sys_id=85728c79c32331006f333b0ac3d3aeb7
ACL script: kb_social_qa_question.*
/sys_security_acl.do?sys_id=408f0263472102007f47563dbb9a713f
Widget server script: link-button
When the portal has no knowledge base configured for its Q&A page, this property supplies the knowledge base used to check whether the user can read it. No default value is passed when the property is read.
/sp_widget.do?sys_id=abc50de6d702120023c84f80de61036a