pillar	category	online version
Operational Excellence	Resource naming	https://github.com/microsoft/PSRule.Rules.CAF/blob/main/docs/rules/en/CAF.Name.Subnet.md

Use standard subnet names

SYNOPSIS

Subnet names should use a standard prefix.

An effective naming convention allows operators to quickly identify resource type, associated workload, deployment environment and Azure region.

For subnets, the Cloud Adoption Framework recommends using the snet- prefix.

Requirements for subnet names:

At least 2 characters, but no more than 80.
Can include alphanumeric, underscore, hyphen, period characters.
Can only start with a letter or number, and end with a letter, number or underscore.
VNET names must be unique within the parent VNET.

Consider creating subnets with a standard name. Additionally consider using Azure Policy to only permit creation using a standard naming convention.

This rule does not check if subnets names are unique.

To configure this rule:

Override the CAF_SubnetPrefix configuration value with an array of allowed prefixes.
Override CAF_UseLowerNames with false to allow mixed case in resource names. By default only lower-case letters and other supported characters are allowed. This option affects all resource name rules.