Natural Objects Locking to avoid concurrent updating

I wish to lock the Natural source (objects) in libraries defined in Natural Security, while maintaining it, to avoid concurrent updating. Because we have common application libraries defined in NSS, where several Developers have full access to it. In Natural 4.2.1 “SLOCK” profile parameter is provided for this purpose, but not in Natural 3.1.6 ? We dont have ADABAS security or SAF. Currently we are on NAT316/ADA742/COM631. But very soon will be migrating to NAT414.

If you have access to ServLine24, SLOCK is described here:

Otherwise, check under Profile Parameters in the documentation - this parameter is new with v4.2 (not 4.1).

Other options include SPoD and PAC for source control in Natural 3.