ldap/servers is a SAP Parameter attribute which is used to control List of LDAP servers for auto registration 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 .
You can use this parameter to specify the servers to be used for
automatic self-registration in an LDAP directory. You can specify any
number of server names, separated by spaces. You can optionally specify
the port to be used with ":<(><<)>Port>". The default port is 389.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.