title: Reference values: string or integer?
body: <p>We have reference values created from a Sequence in a database, which means that they are all integers. (It's not inconceivable - although massively unlikely - that they could change in the future to include letters, e.g. R12345.)</p>
  
  <p>In our [C#] code, should these be typed as strings or integers?</p>
  
  <p>Does the fact that it wouldn't make sense to perform any arithmetic on these values (e.g. adding them together) mean that they should be treated as string literals?  If not, and they should be typed as integers (/longs), then what is the underlying principle/reason behind this?</p>
  
  <p>I've searched for an answer to this, but not managed to find anything, either on Google or StackOverflow, so your input is very much appreciated.</p>