n is either 1 (true) or 0 (false). The default value is 0.
When NullSubscripts is enabled (n = 1), null subscripts are allowed on global references. When this parameter is not enabled, a null subscript causes a <SUBSCRIPT> error. InterSystems recommends leaving this setting disabled.
Changing This Parameter
On the Compatibility page of the Management Portal (System Administration > Configuration > Additional Settings > Compatibility), in the NullSubscripts row, click Edit. Select NullSubscripts to enable this setting.
Instead of using the Management Portal, you can change NullSubscripts in the Config.MiscellanousOpens in a new window class (as described in the class reference) or by editing the CPF in a text editor (as described in the Editing the Active CPF section of the “Introduction to the Configuration Parameter File” chapter in this book).
To change this parameter for a single process only (as opposed to instance-wide), use the NullSubscripts()Opens in a new window method of the %SYSTEM.ProcessOpens in a new window class. See the class reference for details.