"Why, in the Linux world should it matter if I have experience with CentOS instead of Unbreakable?" I think it should matter to employers. No doubt you could l

"Why, in the Linux world should it matter if I have experience with CentOS instead of Unbreakable?" I think it should matter to employers. No doubt you could learn OEL very quickly but I'm sure it has a bunch of little oddities and quirks that could make the day-to-day administration and troubleshooting more difficult for someone without practical OEL experience. From the employer's stand point if they can find someone who knows PAC & OEL inside-out why would they take any chances? It may reflect the job market more than your skill set or the company policies on recruitment. It's very likely they can find a candidate who meets their exact requirements. (Personally I would have just lied and spent the next couple of days learning OEL inside-out to back up my lies)