title: Can I pass custom data in the HTTP header?
body: <p>I have a whole bunch of web services each with several web methods. The consumers of these services are varied and many. I want to augment each of these web methods with an extra optional parameter (Int64 or Int32) but adding new methods with this extra (optional parameter) is a lot of work and getting the clients to use the new methods will be even more time consuming.</p>
  
  <p>So I was wondering if I could allow the clients that wanted to take advantage of the new feature that this param provides could pass this Int in the HTTP header or some other way.</p>
  
  <p>So the first question is can I pass an int in the HTTP header? If so, how would one do that in C#/ASP.NET?</p>
  
  <p>Otherwise, what other suggestions do you have for tackling this problem?</p>