Allowing permissions for a customized Magento extension

Assuming we have developed the following extension to Magento admin panel:

app/code/local/Engineering/Custommodule/

And we can actually use it in the admin panel, but when we would like to set the permissions - we go to System -> Permissions -> Users, and try to give the right permissions to our users.

However, it doesn't seem to work, and the non-administrator users will not be able to view the extension (lack of permissions).

To solve this, we would create a new adminhtml.xml file in app/code/local/Engineering/Custommodule/etc/

Inside the file, we will have the following code:

<?xml version="1.0" encoding="UTF-8"?>
<config>
	<menu>
		<cms> //change to whatever tab you want
			<children>
				<custommodule translate="title" module="custommodule">
					<title>Custom Module</title>
					<action>custommodule/adminhtml_custommodule</action>
				</custommodule>
			</children>
		</cms>
	</menu>
	<acl>
		<resources>
			<admin>
				<children>
					<cms>
						<children>
							<custommodule translate="title">
								<title>Custom Module</title>
								<sort_order>0</sort_order>
							</custommodule>
						</children>
					</cms>
				</children>
			</admin>
		</resources>
	</acl>
</config>