[Home](./index.md) > [sip.js](./sip.js.md) > [UserAgentOptions](./sip.js.useragentoptions.md) > [sipExtensionExtraSupported](./sip.js.useragentoptions.sipextensionextrasupported.md) ## UserAgentOptions.sipExtensionExtraSupported property Extra option tags to claim support for. Signature: ```typescript sipExtensionExtraSupported?: Array; ``` ## Remarks Setting an extra option tag does not enable support for the associated extension it simply adds the tag to the list of supported options. See [UserAgentRegisteredOptionTags](./sip.js.useragentregisteredoptiontags.md) for valid option tags.