I experience issues with property type tags when editors use the & character in tags, e.g. "Research & Development".

My setup is this:

First, I check the URL for a topic value.

var topic = string.Empty;
topic = string.IsNullOrEmpty(Request["t"])
  ? string.Empty
  : Request["t"];

I then transform the value to lowercase.

var topicLow = topic.ToLower();

Finally I look for the lowercase topic value in an array named "everything".

var myResult = everything.Where( x => x.Value<string[]>("topicTags").Select(s => s.ToLowerInvariant()).ToArray().Contains(@topicLow) );

This works just fine in most cases, just not when the topic tag contains a & character.

Possible reasons for this issue and suggestions for solutions will be much appreciated.