# Managing devices with AWS IoT

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This page was generated from content adapted from the [AWS Developer Guide](https://github.com/awsdocs/aws-iot-docs.git)
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## How to manage things with the registry

* **Note**\
  We don't recommend using personally identifiable information in your thing names.

## Thing types

* **Note**\
  You must wait five minutes after you deprecate a thing type before you can delete it.

## Static thing groups

* **Note**\
  We don't recommend using personally identifiable information in your thing group names.
* **Important**\
  Keep in mind the following limits when creating thing group hierarchies:\
  A thing group can have only one direct parent. The number of direct child groups a thing group can have is [limited](https://docs.aws.amazon.com/general/latest/gr/iot_device_management.html#thing-group-limits). The maximum depth of a group hierarchy is [limited](https://docs.aws.amazon.com/general/latest/gr/iot_device_management.html#thing-group-limits). The number of attributes a thing group can have is [limited](https://docs.aws.amazon.com/general/latest/gr/iot_device_management.html#thing-group-limits). (Attributes are name-value pairs you can use to store information about a group.) The lengths of each attribute name and each value are also [limited](https://docs.aws.amazon.com/general/latest/gr/iot_device_management.html#thing-group-limits).
* **Important**\
  You can add a thing to a maximum of 10 groups. But you can't add a thing to more than one group in the same hierarchy. (In other words, you can't add a thing to two groups which share a common parent.)\
  If a thing belongs to as many thing groups as possible, and one or more of those groups is a dynamic thing group, you can use the <https://docs.aws.amazon.com/iot/latest/apireference/API_AddThingToThingGroup.html#iot-AddThingToThingGroup-request-overrideDynamicGroups> flag to make static groups take priority over dynamic groups.
* **Note**\
  This operation is [eventually consistent](https://web.stanford.edu/class/cs345d-01/rl/eventually-consistent.pdf). In other words, changes to the thing group might not be reflected immediately.
* **Note**\
  This operation is [eventually consistent](https://web.stanford.edu/class/cs345d-01/rl/eventually-consistent.pdf). In other words, changes to the thing group might not be reflected immediately.
* **Note**\
  The number of attributes that a thing can have is [limited](https://docs.aws.amazon.com/general/latest/gr/iot_device_management.html#thing-limits).
* **Important**\
  If you try to delete a thing group that has child thing groups, you receive an error:
* **Important**\
  You can attach a maximum number of two policies to a group.
* **Note**\
  We don't recommend using personally identifiable information in your policy names.

## Dynamic thing groups

* **Note**\
  We don't recommend using personally identifiable information in your dynamic thing group names.
* **Note**\
  After you create a dynamic thing group, you can use the group, regardless of its status. Only dynamic thing groups with an `ACTIVE` status include all of the things that match the search query for that dynamic thing group. Dynamic thing groups with `BUILDING` and `REBUILDING` statuses might not include all of the things that match the search query.
* **Note**\
  If you have permissions to query the fleet index, you can access the data of things across the entire fleet.