What is the default behavior for items added to System.Web.Caching.Cache?
<p>What are the default expiration parameters associated with items added to the ASP.NET cache?</p>

<p>Do items added expire after an absolute period of time, and if so, what is the default expiration time? Or do they use a sliding-window?</p>

<p>I can't seem to find any references to default behavior of items added and I need to know because I am supporting a code-base where all calls to the Cache are done via Cache[key] = value rather than specifying explicit dependencies / expiration policies </p>
