!!! Overview
[{$pagename}] is a [Certificate Extensions] and consists of a list of usages indicating purposes for which the certificate public key can be used for.

These can either be object short names of the dotted numerical form of [OIDs]. While any [OID] can be used only certain values make sense. In particular the following [PKIX], NS and MS values are meaningful: (Not an complete list)
%%zebra-table
%%sortable
%%table-filter
||[OID]||String||REF||Meaning
|[1.3.6.1.5.5.7.3.1]|[serverAuth]|[RFC 3280]|SSL/TLS Web Server Authentication.
|[1.3.6.1.5.5.7.3.2]|[clientAuth]|[RFC 3280]|SSL/TLS Web Client Authentication.
|[1.3.6.1.5.5.7.3.3]|[codeSigning]|[RFC 3280]|Code signing.
|[1.3.6.1.5.5.7.3.4]|[emailProtection]|[RFC 3280]|E-mail Protection (S/MIME).
|[1.3.6.1.5.5.7.3.5]|[ipsecEndSystem]|[RFC 3280]|IP security end system
|[1.3.6.1.5.5.7.3.6]|[timeStamping]|[RFC 3280]|IP security tunnel termination
|[1.3.6.1.5.5.7.3.7]|[timeStamping]|[RFC 3280]|IP security user
|[1.3.6.1.5.5.7.3.8]|[timeStamping]|[RFC 3280]|Trusted Timestamping
|[1.3.6.1.5.5.7.3.9]|[OCSPstamping]|[RFC 3280]|OCSPstamping
|[1.3.6.1.4.1.311.2.1.21]|[msCodeInd]|[Microsoft]|[Microsoft] Individual Code Signing ([authenticode])
|[1.3.6.1.4.1.311.2.1.22]|[msCodeCom]|[Microsoft]|[Microsoft] Commercial Code Signing ([authenticode])
|[1.3.6.1.4.1.311.10.3.1]|[msCTLSign]|[Microsoft]|[Microsoft] Trust List Signing
|[1.3.6.1.4.1.311.10.3.3]|[msSGC]|[Microsoft]|Microsoft Server Gated Crypto
|[1.3.6.1.4.1.311.10.3.4]|[msEFS]|[Microsoft]|Microsoft Encrypted File System
|[2.16.840.1.113730.4.1]|[nsSGC]|[Netscape]|Netscape Server Gated Crypto
/%
/%
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! [Examples]:
%%prettify 
{{{
extendedKeyUsage=critical,codeSigning,1.2.3.4
extendedKeyUsage=nsSGC,msSGC
}}} /%

!! More Information
There might be more information for this subject on one of the following:
[{ReferringPagesPlugin before='*' after='\n' }]
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* [#1] - [Object IDs associated with Microsoft cryptography|https://support.microsoft.com/en-us/help/287547/object-ids-associated-with-microsoft-cryptography|target='_blank'] - based on information obtained 2020-02-16