Bug#1041993: is URIs supposed to be a list?

[Marc Haber <mh+debian-packages@zugschlus.de>]

Package: apt
Version: 2.7.2
Severity: minor

Hi,

in sources.list(5), the deb822 field for the URI is named "URIs". But
all examples have just one URI.

Is this supposed to be a list? What would be the semantics of multiple
URIs given there? Could I list there multiple Debian mirrors with apt
doing (concurrent, round-robin, first answering wins?) using all of
them?

Please elaborate in the docs about this possibility or make it clear
that despite the plural apt just expects a single URI.

Greetings
Marc