diff --git a/README.md b/README.md
index c9b28b2..2acdea3 100644
--- a/README.md
+++ b/README.md
@@ -261,13 +261,15 @@ for a specific attribute. An optional **to_ids** boolean field to disable the ID
 - [objects/network-socket](https://github.com/MISP/misp-objects/blob/main/objects/network-socket/definition.json) - Network socket object describes a local or remote network connections based on the socket data structure.
 - [objects/news-agency](https://github.com/MISP/misp-objects/blob/main/objects/news-agency/definition.json) - News agencies compile news and disseminate news in bulk.
 - [objects/news-media](https://github.com/MISP/misp-objects/blob/main/objects/news-media/definition.json) - News media are forms of mass media delivering news to the general public.
+- [objects/open-data-security](https://github.com/MISP/misp-objects/blob/main/objects/open-data-security/definition.json) - An object describing an open dataset available and described under the open data security model. ref. https://github.com/CIRCL/open-data-security.
 - [objects/organization](https://github.com/MISP/misp-objects/blob/main/objects/organization/definition.json) - An object which describes an organization.
 - [objects/original-imported-file](https://github.com/MISP/misp-objects/blob/main/objects/original-imported-file/definition.json) - Object describing the original file used to import data in MISP.
 - [objects/paloalto-threat-event](https://github.com/MISP/misp-objects/blob/main/objects/paloalto-threat-event/definition.json) - Palo Alto Threat Log Event.
 - [objects/parler-account](https://github.com/MISP/misp-objects/blob/main/objects/parler-account/definition.json) - Parler account.
 - [objects/parler-comment](https://github.com/MISP/misp-objects/blob/main/objects/parler-comment/definition.json) - Parler comment.
 - [objects/parler-post](https://github.com/MISP/misp-objects/blob/main/objects/parler-post/definition.json) - Parler post (parley).
-- [objects/passive-dns](https://github.com/MISP/misp-objects/blob/main/objects/passive-dns/definition.json) - Passive DNS records as expressed in draft-dulaunoy-dnsop-passive-dns-cof-01.
+- [objects/passive-dns](https://github.com/MISP/misp-objects/blob/main/objects/passive-dns/definition.json) - Passive DNS records as expressed in draft-dulaunoy-dnsop-passive-dns-cof-07. See https://tools.ietf.org/id/draft-dulaunoy-dnsop-passive-dns-cof-07.html.
+- [objects/passive-dns-dnsdbflex](https://github.com/MISP/misp-objects/blob/main/objects/passive-dns-dnsdbflex/definition.json) - DNSDBFLEX object. This object is used at farsight security. Roughly based on Passive DNS records as expressed in draft-dulaunoy-dnsop-passive-dns-cof-07. See https://tools.ietf.org/id/draft-dulaunoy-dnsop-passive-dns-cof-07.html.
 - [objects/paste](https://github.com/MISP/misp-objects/blob/main/objects/paste/definition.json) - Paste or similar post from a website allowing to share privately or publicly posts.
 - [objects/pcap-metadata](https://github.com/MISP/misp-objects/blob/main/objects/pcap-metadata/definition.json) - Network packet capture metadata.
 - [objects/pe](https://github.com/MISP/misp-objects/blob/main/objects/pe/definition.json) - Object describing a Portable Executable.