One of our RSS feed URL's has been https://neighborsofchampaign.com/feed?cat=-4
originally set to pull our General News feed from a Wordpress site. These RSS feeds are being used with MailChimp campaigns.
Other specific Wordpress categories are formatted https://www.neighborsofchampaign.com/?cat=210&feed=rss2
1. What is the -4 value effect on the RSS feed? Note: the actual category ID for General News is 3 in our case.
2. Is the domain/?cat=xxx&feed=rss2 the formal way to format rev 2 of RSS?