[#RPCArg-Optional] = xref:RPCArg.adoc[RPCArg]::Optional :relfileprefix: ../ :mrdocs: Whether an argument is required or may be omitted. == Synopsis Declared in `<rpc/util.h>` [source,cpp,subs="verbatim,replacements,macros,-callouts"] ---- enum class Optional : int; ---- == Members [cols="1,4"] |=== | Name| Description | `NO` | Required arg | `OMITTED` | Optional argument for which the default value is omitted from help text for one of two reasons: ‐ It's a named argument and has a default value of `null`. ‐ Its default value is implicitly clear. That is, elements in an array may not exist by default. When possible, the default value should be specified. |=== [.small]#Created with https://www.mrdocs.com[MrDocs]#