diff --git a/docs/globally-unique-domain-zone.md b/docs/globally-unique-domain-zone.md
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+# Globally unique domain zone
+
+**Make sure you understand the [basic concepts](../nns/README.md) of `NNS`.**
+
+`Globally Unique Domains Zone` (`GUDZ`) is an extension of `NNS` that ensures unique names across multiple domain zones. When this option is enabled, all newly created domains will automatically receive a corresponding alias in the designated global zone. Deleting a domain will also remove its alias from the global zone.
+
+It's important to note that this feature is not retroactive: domains created before this option is enabled will not receive a global alias. Likewise, if the option is later disabled, domains that already have a `GUDZ` alias will retain their records. To fully disable `GUDZ`, all domains must be recreated with the option turned off.
+
+To enable `GUDZ`, add a `cnametgt=$(global domain)` `TXT` record that specifies the global zone.
+
+**Example:**
+
+Domains:
+- `poland`
+- `sweden`
+- `animals.org`
+
+It is necessary to associate the domain zones `.poland` and `.sweden` into the global zone `.animals`.
+
+
+
+Create domains:
+
+```
+frostfs-adm morph nns register --name="poland" --email="email@email.email"
+frostfs-adm morph nns register --name="sweden" --email="email@email.email"
+frostfs-adm morph nns register --name="org" --email="email@email.email"
+frostfs-adm morph nns register --name="animals.org" --email="email@email.email"
+```
+
+Add the `cnametgt` records:
+
+```
+frostfs-adm morph nns add-record --name="poland" --data="cnametgt=animals.org" --type="txt"
+frostfs-adm morph nns add-record --name="sweden" --data="cnametgt=animals.org" --type="txt"
+```
+
+Create a domain with mapping to the global zone:
+
+```
+frostfs-adm morph nns register --name="bober.poland" --email="email@email.email"
+```
+
+Add any `TXT` record
+
+```
+frostfs-adm morph nns add-record --name="bober.poland" --data="CID" --type="txt"
+```
+
+Verify that the created domain has alias in the global zone
+
+```
+frostfs-adm morph nns tokens -v
+
+balance.frostfs
+animals.org
+group.frostfs
+container
+org
+container.frostfs
+proxy.frostfs
+policy.frostfs
+alphabet0.frostfs
+sweden
+frostfsid.frostfs
+bober.animals.org (CNAME: bober.poland)
+netmap.frostfs
+frostfs
+poland
+bober.poland
+```
+
+Create of a conflicting domain
+```
+frostfs-adm morph nns register --name="bober.sweden" --email="email@email.email"
+
+unable to register domain: script failed (FAULT state) due to an error: at instruction 1263 (THROW): unhandled exception: "global domain is already taken: bober.animals.org. Domain: bober.poland
+```
+
+**Disable GUDZ**
+Delete `cnametgt` records
+
+```
+frostfs-adm morph nns delete-records --type=txt --name=poland
+```
+Create `hamster.poland` and `hamster.sweden`
+```
+frostfs-adm morph nns register --name="hamster.poland" --email="email@email.email"
+frostfs-adm morph nns register --name="hamster.sweden" --email="email@email.email"
+```
+`hamster.poland` and `hamster.sweden` does not have alias
+```
+frostfs-adm morph nns tokens -v
+balance.frostfs
+animals.org
+group.frostfs
+container
+org
+container.frostfs
+proxy.frostfs
+policy.frostfs
+alphabet0.frostfs
+sweden
+frostfsid.frostfs
+bober.animals.org (CNAME: bober.poland)
+netmap.frostfs
+frostfs
+poland
+bober.poland
+hamster.poland
+```
+Delete global alias of `bober.poland`
+
+```
+ frostfs-adm morph nns delete-records --name="bober.poland" --type="txt"
+```
+
+
+```
+frostfs-adm morph nns tokens -v
+balance.frostfs
+animals.org
+group.frostfs
+container
+org
+container.frostfs
+proxy.frostfs
+policy.frostfs
+alphabet0.frostfs
+sweden
+frostfsid.frostfs
+netmap.frostfs
+frostfs
+poland
+bober.poland
+hamster.poland
+```
+Delete `bober.poland`
+```
+ frostfs-adm morph nns delete --name="bober.poland"
+```
+
+```
+frostfs-adm morph nns tokens -v
+balance.frostfs
+animals.org
+group.frostfs
+container
+org
+container.frostfs
+proxy.frostfs
+policy.frostfs
+alphabet0.frostfs
+sweden
+frostfsid.frostfs
+netmap.frostfs
+frostfs
+poland
+hamster.poland
+```
\ No newline at end of file
diff --git a/docs/img/GUDZ.drawio b/docs/img/GUDZ.drawio
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diff --git a/docs/img/GUDZ.png b/docs/img/GUDZ.png
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diff --git a/nns/README.md b/nns/README.md
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+# NNS
+NNS - Neo Name Service is a service that allows manage a domain name as a digital asset (NFT). It has an interface similar to `DNS` but has significant differences in its internal structure.
+
+## Entities:
+
+- Domain
+- Record
+- Owner
+- Committee
+
+### Domain
+
+Domain is string that satisfies the following requirements:
+- Length from 2 to 255 characters.
+- Root domain must start with a letter.
+- All other fragments must start and end with a letter or digit.
+
+Domain has owner, a registration period, and may optionally have records.
+
+A fee established by the committee is charged upon domain registration. After registration, the owner can manage this asset (add/delete records, transfer ownership to another owner) until the end of the domain registration period.
+
+### Record
+
+A record is a pair of values ``.
+
+Supported record types:
+
+| Type | Description |
+|-------|-------------------------------------------|
+| A | Represents address record type |
+| AAA | Represents IPv6 address record type |
+| TXT | Represents text record type |
+| CNAME | Represents canonical name record type |
+| SOA | Represents start of authority record type |
+
+### Owner
+
+An owner is a wallet that has the right to manage this NFT (domain).
+
+### Committee
+
+The committee makes new tokens (domains), sets, and charges a fee for issuance.
+
+## Globally Unique Domain Zone
+
+For more information, see [here](../docs/globally-unique-domain-zone.md).