login/ticket_only_to_host is a SAP Parameter attribute which is used to control ticket will only be sent back to creating host information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
Specifies how the system sets the logon ticket generated at logon using
http(s) in the browser.
0: Ticket is sent with requests to all servers in the domain.
1: Ticket is sent only with requests to the server that created the
ticket.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.