`Stream.Length` docs ambiguous

The docs for `Stream.Length` currently say:

> When overridden in a derived class, gets the length in bytes of the stream.

This is ambiguous, in the sense that I felt the need to spin up `dotnet fsi` to confirm to myself that I had picked the correct interpretation. Does it mean "the *remaining* length", or "the *absolute* length"? Of course it means "absolute", and most people will probably choose that interpretation anyway, but in a scenario where the `Stream` represents "forgetting everything that came before", it may be natural to interpret it as "remaining" (because the `Stream` has forgotten its past!).

I don't have a *great* suggestion for an improvement, but perhaps a remark to the effect that "in a stream which supports `Seek`, this is expected essentially to be the value of `Position` after `Seek(0L, SeekOrigin.End)`"? (`Position` is much more natually an absolute concept, because you can `Seek` backwards.) Or perhaps "When overridden… gets the total length in bytes of the stream"?