# Host naming This section describes the host naming pattern that you specify on the [**Properties**](/landing/ras-admin-guide/parallels-ras-21-administrators-guide/virtual-desktop-infrastructure-vdi/manage-vdi/manage-templates-vdi/creating-a-vm-template/step-2-configure-the-template/properties.md) page of the template creation wizard. Each time a new host is created, a name for it is generated automatically based on the pattern that you specify in the **Host name** field. The complete name format is as follows: `%ID:N:S%` where: * **\** is an alphanumeric string that must begin with a letter (not a digit). * **%ID:N:S%** is a numeric pattern used to automatically generate a unique host ID. See the **Numeric pattern** subsection below. * **\** is a free-form alphanumeric string. ## **Numeric pattern** The numeric pattern in the VM name has the following format: `%ID:N:S%` The elements in the pattern above are: * **ID** — Must be included as is. * **N** — The number of digits to use, including leading zeros. Use "0" if you don't want to insert leading zeros. * **S** — The starting number. This element is optional. If you don't include it, the number will start with 1. ## **Examples:** * `%ID:3%` — This pattern will generate 3 digit numbers with leading zeros, such as "001", "002", "003"...."998", "999". * `%ID:3:200%` — This example will generate 3 digit numbers starting from 200, such as "200", "201", "202"..."998", "999". * `VDI-R1-%ID:3:100%` — This is a complete name with an alphanumeric prefix and a numeric pattern. The resulting names will look like the following: "VDI-R1-100", "VDI-R1-101", etc. When crating a name pattern, follow the rules listed below. If any of these rules are not observed, you will see an error message and will have to correct it: * The name must start with a letter. A digit is not allowed as the first character. * The alphanumeric part of a name can contain letters, digits, and a hyphen. No other characters are allowed. * The total length of the name must not exceed 15 characters. * The name can include just one numerical pattern (`%ID:N:S%`), which must be placed at the end or in the middle of the name. The pattern that you specify is also validated against the value of the **Maximum hosts** field. If the pattern doesn't cover the maximum number of hosts, you will get an error and will have to correct it. ## **Reusing VM numbers in a name** When you delete a host, the number that was assigned to it becomes unused. The next host that is created will be given this number, so there are no gaps in numbering. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.parallels.com/landing/ras-admin-guide/parallels-ras-21-administrators-guide/virtual-desktop-infrastructure-vdi/manage-vdi/manage-templates-vdi/creating-a-vm-template/step-2-configure-the-template/host-naming.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.