Typically when convering to a newer numbered version of 4D, some commands may become obsolete. Obsolete commands are prefixed with the string "_O_" (E.G. _O_String) and are only kept for compatibility or legacy reasons. However, this does not mean that the command will continue to be supported some time in the future and is recommended to replace them with its newer command counterpart.

In order to quickly find all obsolete commands in the database, simply go to the top menu bar and navigate to Edit > Find in design and search for the "_O_" prefix.



Once the search result screen appears, you can click on where that line appears in a method, place the cursor over the command, and hit F1 to open up the documentation to find out which command replaces the obsolete command.