This is my first post to this group so these things may or may not be
obvious and/or silly. If so, I apologize in advance.

  Firstly, I'm not new to POV, having started with the DOS version many
years ago with a copy that was included in the book 'Ray Tracing Creations'.
Despite my long time acquaintance with POV I have really only dabbled from
time to time, never building anything truly complex. For me, I enjoy POV's
math and geometry as much as the finished images. Bizarre isn't it?  Anyway,
on to my current problems:

  I've noticed that some object modifiers are not universal in their usage
and only work on certain objects or need to be specified in a certain order
when used on specific objects. Since the documentation is spotty in a few
areas and perhaps incorrect in a select few cases I decided to see if anyone
could clear up a few of the following things for me:

  I can not seem to get the angle keyword to have any effect whatsoever with
panoramic cameras despite the documentation's claim to the contrary. More
generally, I'd like to know which camera types should use the various values
like up,direction,right, and angle and in what order they should be
specified (since this seems to make a difference).

  I'm also not quite clear on the usage of certain keywords. I've noticed
sturm can be used on prism spline types not mentioned in the documentation
and was wondering if there was a reason for this not being mentioned, like
perhaps it shoudn't be used in these cases. Also, can hollow and inverse be
applied to any object, even non-solid ones? It seems to be allowed, although
I cannot understand what hollow would do to a bicubic patch, for example.

  Finally, I noticed that the water-level modifier for height fields will
generate an error if placed after the hierarchy keyword. Is this a bug or is
there a reason for this that I just don't see. Are there other instances of
objects/cameras/lights that require keywords in a certain order to function
properly?

Thanks in advance for any assistance.

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