Why would anyone delete a clish configuration command = this idea itself is rather sick, as i can think of no reason for such a wish.
I have found that the command is present in R81.10, too:
GWS76> set dns
GWS76> set dns
CLINFR0339 Incomplete command.
GWS76> set dns
mode - DNS mode
primary - Primary DNS Server
proxy - Set DNS Proxy related values
secondary - Secondary DNS Server
suffix - DNS suffix
tertiary - Tertiary DNS Server
GWS76> set dns
mode - DNS mode
primary - Primary DNS Server
proxy - Set DNS Proxy related values
secondary - Secondary DNS Server
suffix - DNS suffix
tertiary - Tertiary DNS Server
It is also present on GAiA Embedded at least since R80.20.xx and in GAiA at least since R80.40, see https://sc1.checkpoint.com/documents/R80.40/WebAdminGuides/EN/CP_R80.40_Gaia_AdminGuide/Topics-GAG/H...
CCSP - CCSE / CCTE / CTPS / CCME / CCSM Elite / SMB Specialist