According to this article from Broadcast Engineering, the standards working group of POPAI's digital signage organization has announced its first set of non-technical standards, starting at the very beginning: terminology.  This is a noteworthy announcement, since like with any emerging marketplace, we in the digital signage industry tend to create new terminology when an existing word or phrase doesn't quite fit the bill.  The result has been a plethora of terms coming out of digital sign and narrowcasting firms and research organizations, and consequently a good deal of customer confusion.  Below is the first set of terms that the standards group has proposed, along with their definitions.  I've interjected my own thoughts in blue text.  The Broadcast Engineering article states that the working group has asked for feedback, but I haven't been able to find the location on POPAI's site that allows for this yet.  I'll update this article if I do come across a suitable place to post feedback, but without further ado, here's the list:

• Digital signage: A network of digital displays that are centrally managed and addressable for targeted information, entertainment, merchandising and advertising. Synonyms: dynamic signage, digital signs, electronic signage, digital media advertising, digital signage network, in-store TV network, captive audience network, narrowcasting network, out-of-home media network, digital media network, advertising network.
  
  This is the big one, in my opinion, and while it's good to see that they did actually formally define digital signage as a centrally managed network of digital signs, I think the definition might still be too complex for some lay-people.  Though I'm a huge fan of simplicity in general, I think this definition needs more text, perhaps something like:
  "Any kind of electronic display (such as a TV, computer monitor, or flat screen) that can be remotely controlled over a computer network (like the Internet) and is placed into a venue to show targeted information, content and advertisements."  I also would have ditched the synonym list, but that's just because I don't like having a list of ten terms that mean the same thing, and I think that some terms like "captive audience network" and "narrowcasting" could mean very different things.  In the interest of reaching the widest possible audience, though, I can understand why they put them in.  At least they didn't include Avanti's self-styled "screenmedia" :)
  


• Content distribution server: A computer, server, or device that stores the contents that are distributed to the player in the store. Synonyms: broadcast server, network manager, content management server.
  
  This definition is fine, however I wonder if they were planning to denote the difference between a "central server" and a "site server," which some digital signage products make use of.  For example, a typical FireCast digital signage setup would involve a number of individually-addressable players in the field each connecting to our central server cluster, ClientCenter. This is called a 2-tier system, because there is only one central point (the server) and the endpoints (the digital sign players).  However, in some setups, there is another server located at each store, which houses additional content, data feeds, etc. that would be harder to manage centrally.  In these 3-tiered solutions, we still have the central server and digital sign players, but we also have site servers (one per site).  Both of these types of servers would qualify as "content distribution servers" under the above definition, but clearly they are different in their topology and functionality.
  


• Channel: Script that has been published in such a way that when its contents change, the updated material is forwarded to machines running the viewer that have subscribed to the channel. Synonym: zone.
  
  I like this definition, but dislike the synonym.  When talking to customers we typically address things like pricing and content creation by using the term "channel" exactly as it is above.  Most people seem to grasp it pretty quickly since they're familiar with how a TV or cable channel works.  The synonym "zone," on the other hand, doesn't really fit in this case.  While I'm sure they're using it to refer to a "geographic zone" or something like that, we most often see "zone" used interchangeably with words like "region," "banner" or "frame" to denote a specific area of a screen that has been divided up (e.g. the classic digital signage layout including a 4:3 video area, a tower area, and a ticker along the bottom).
  


• A/V distribution system: The distribution of multimedia content from the player to the display device.
  
  This looks good to me.  Nice, simple, and obviously not intended to go into the multitude of distribution systems available today, like video over CAT-5, video over IP, video over wireless, PCI or PCI-E bridged over fiber, video baluns, scalers, or good ol' really, really long VGA cables.
  


• Display device: CRT, flat panel LCD, plasma, projector or other devices that are at the end-point of a digital signage system.
  
  Also fine by me.  The way these definitions are set up sort of reminds me of how patent or contract definitions are often created.  You define one thing that contains elements that are themselves defined elsewhere.  That's why in the original definition of digital signage above they use the term "display device" without having to say that a display device might be a TV, LCD, etc.  Also, it's a pretty simple term, so hopefully most people will be able to understand it without referring to a formal definition.
  


• Player: Distributes A/V content to a display.
  
  To be terminologically correct (and consistent), it should probably say Distributes A/V content to a display device, thus making use of the previous definition.  And actually, I'm not terribly satisfied with this definition, since it doesn't really capture what a player is.  In any modern digital signage network (especially a networked digital signage system, as defined above), a player is a computer of some sort that drives the display device.  Its responsibilities include downloading the appropriate data for its display (since players are typically individually addressable), and then translating that content from its downloaded/stored form into a form that the display device can actually show.  So my revised definition might be something like, "a computer-like device that receives the appropriate content from the content distribution server, and outputs it to one or more display devices (possibly through an A/V distribution system)."
  


• Multichannel player: Outputs multiple streams of unique content to multiple display devices. Synonyms: site server, in-Store server.
  
  In FireCast-land, a multichannel player and a site server are two very different things, though I realize that this might not be the case for some other products.  I think it partly stems from our ability to drive interactive kiosks and digital signs using the same platform.  Typically, a kiosk has the computer built in to its cabinet, so that multiple peripherals like touchscreens, mice, trackballs, card swipes, etc. can be plugged in to the serial and usb ports.  Digital signs often don't need those extra things, and can be driven by players that are not physically near the display devices themselves. (Did you notice I've started to use the official parlance?)  If the working group intends for these to be used interchangeably, fine, but I think it might limit the usefulness of the term.  My revised definition would be "A player that is capable of driving different content channels to more than one display device at once."
  


• Content: Media, clips, text, video and audio that is delivered to display devices by a digital signage system.
  
  Good.  If anybody doesn't understand this definition, they probably shouldn't be working with digital signage.
  


• Playlog: Record of information created from the digital signage system reflecting the content played, the system performance and other data. Synonyms: billing log, performance log, audit Log.
  
  I think this one is good also, however in FireCast (as with many other packages) we can generate both play logs (focusing on content played)and system logs (focusing on system performance, network errors, etc.).
  


• Playlist: Composed of a list of clips and their play order by time or other heuristics.
  
  This is another tough one, and I've seen it called everything from playlists to scripts to campaigns to carousels (thanks to Netshift -- now NS Systems Ltd. -- for that one).  Of all the terms I've heard, I do like "playlist" the best.  Again, though, I might shift the actual definition to take into account more of the defined terms, as in, "a list of content files which are either played in order, or randomized according to some set of heuristics (rules)."
  

In all, I think this list is a great start, and I applaud the efforts of the standards working group in getting this far.  I think that a lot of future confusion can be avoided by using industry-standard terms that can be defined and looked up.  The challenge will be ensuring that the terms are defined in such a way that they are useful to a wide audience of vendors, researchers and users alike.