Editing Security.pl (section)

== can_request_view_document ==
This function determines whether a general request can access a particular document.  The default function will do the following checks:
# If the document is public and the eprint is in the live archive and returns ''ALLOW'' if that is the case.
# If there is a "request a copy" code and if that code's request is for permitting access to the document and has not expired and returns ''ALLOW'' if that is the case.
# If there is a "request a copy" code and coversheets is enabled and the code's request is for permitted for the original document from which the coversheeted version now being accessed is generated and the request has not expired.  If this is the case ''ALLOW'' is returned.
If none of the criteria are meet then ''USER'' is returned.

If the default version of this configuration file, there is commented out code for allowing authenticated access for a web crawler or permitting specific IP addresses for scenarios like on campus access.