++ What is a slug?
Derived from slugs in newspaper editing: http://en.wikipedia.org/wiki/Slug_%28production%29
++ Slug specification for Horde
Slugs are letters (upper or lower case), numbers, underscore () and dash (-). The PCRE regex is: [a-zA-Z0-9-]+
how long?
++ Autogeneration
++ !JavaScript support
++ URL rewriting
you can't create slugs with hyphens or underscores, even though these are valid in urls
the character limit is quite short (longer titles can be useful for SEO).
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and a few usability enhancements...
javascript to auto-generate the slug based on the form title would be nice. Similar to how EE does things, when the slug field is empty, as a user types in the page title, the slug is generated, converting spaces to underscores or hyphens (could be config, or default to underscore). Once the slug input has a value, changing the title doesn't change the slug.
display a warning if a user tries to change the slug after a form has already been saved ("Warning: changing the slug will cause the link for this form to change.")