Item identifiers, also known as URL names in LabelEd are an important navigational feature of your site.
When creating a new item or category, you can specify any identifier you wish, although they must be unique and can only contain letters, numbers and a few special characters such as hyphens and underscores.
This identifier is then used on your website to make up the URL (Uniform Resource Locator) of the related page.
Friendly URLs make browsing your site more meaningful for your visitors, and they also help search engines rank your content appropriately.
You should always aim to make your identifiers fairly short but specific to the content of the page or item.