collection id aliases

All,
Re: GitHub issue 90 ( https://github.com/oasis-tcs/cti-taxii2/issues/90 )
Please review and help improve the following text from section 5.2.1 in Working Draft 04. Please note the the URL safe character line needs to be change to be standards compliant language that references RFC 3986 or something  like that.
alias
(optional)
string
A  human readable collection name that can be used on systems to alias a collection ID. This could be used by organizations that want to preconfigure a known collection of data, regardless of the
underlying
collection
ID that is configured on a specific implementations.
The  alias value
MUST
use URL safe characters.
If  defined, the alias MUST be unique within a single api-root on a single TAXII server. There is no guarantee that an alias is globally unique across api-roots or TAXII server instances.
Example: /{api-root}/collections/critical-high-value-indicators/
Thanks
Bret