Ken,
You are right as usual.
http://www.cirfs.org/03_02.htmIt's polymerises into much shorter chains which because of the nature of the chemical groups do not align very well, making it much less resistant to water than the long chain crystalised polymers such as nylon,plypropylene,acrylic(dralon),polyester etc.
It also has a much olwer wet strength than cotton so needs treating with care.
On a practical level colours sometimes run , particularly reds and pile can dry stiff so best to lay it down with a towell.
There is much less viscose around now than when I started so less likely to come across it.
One of the main things that complicates fibre identification is the common practice of blending different fibres.
Cheers
Doug