A portière is a curtain that hangs in a doorway. It has a dual function: privacy and heat conservation. It stands in where a door would be clunky and inconvenient. Unfortunately, other than the beaded curtain fad of the 1960s, the portière seems to have disappeared. Was it because those beaded curtains messed up your big hair?
Though, it should be noted, the beaded curtain predates Ann-Margaret:
But I digress.
The Japanese have a version of the the portière called Noren (暖簾) that can be found both inside and outside homes and businesses. According to Wikipedia,
Exterior noren are traditionally used by shops and restaurants as a means of protection from sun, wind, and dust, and for displaying a shop’s name or logo. Names are often Japanese characters, especially kanji, but may be mon emblems, Japanese rebus monograms, or abstract designs. Noren designs are generally traditional to complement their association with traditional establishments, but modern designs also exist. Interior noren are often used to separate dining areas from kitchens or other preparation areas, which also prevents smoke or smells from escaping.
The August 1903 issue of Gustav Stickley’s The Craftsman has a few pages devoted to portières. At over $200 each in today’s dollars, these were luxury items. 
The very same portal that allows our UPS driver a full view of our bathroom has the telltale evidence of a past portière. In the doorway you can see the holder for a curtain rod that once held a portière.
In the name of modesty, I’ve added the portière to my long house restoration bucket list.