Rose City Til I Die means that you follow the Rose City, specifically the Portland Timbers and would never support the Shittle Flounders even if Portland doesn't have a team.
Tool: "Hey you going to see the X-box team play up north?"
Me: "Hell NO RCTID you whale fucker!"
Rangers 'til I die - the state of being a loyalfan of a team called Rangers (Glasgow, QPR) with so much passion that you'll support them until your death.
Boy 1: Hi, I'm a Chelsea fan Boy 2: Get out, I'm RTID!