1 files changed, 47 insertions, 13 deletions
diff --git a/docs/USERGUIDE.md b/docs/USERGUIDE.md
index 1790475..ea81c76 100644
--- a/docs/USERGUIDE.md
+++ b/docs/USERGUIDE.md
@@ -297,6 +297,19 @@ file browser — sort, select, download, preview.
 - **Right-click a file or folder** for the same actions as the toolbar, listing
   only the ones that apply to it. On a ticked row the menu acts on everything
   ticked, like the toolbar does.
+- **A link to a group, a folder or a file.** While a group is open the address
+  bar shows `https://<hub>/#/name@owner` — the name under the group's title.
+  Add a path after it to point inside the group:
+  `#/name@owner/root/folder/photo.jpg` downloads that file, and a folder opens
+  Files there. Only members get anywhere with such a link — anyone else is told
+  the group is unknown — and someone not signed in is asked to sign in first,
+  then taken where the link pointed. Renaming the group breaks these links.
+- **Copy link** gives you that address for one file or folder: right-click it,
+  or tick it and use the link button in the toolbar (the way on a phone). Music
+  has it in a track's menu (**⋯** on a phone), Photos when you right-click a
+  photo or in the photo viewer's bar, and the video player and file preview
+  have a link button next to Download. Search offers the same, pointing at the
+  group each result comes from.
 
 ### Chat
 
@@ -352,7 +365,9 @@ An album browser and a player, over the folders the operator chose for it.
 ### Photos
 
 An album browser over the folders the operator chose for it, where **an album
-is a folder**. Thumbnails come from the node, already rotated correctly.
+is a folder**. Thumbnails come from the node, already rotated correctly. A
+photo opens full size, with a slideshow button that moves on every five
+seconds and stops at the album's last photo.
 
 **Location data is never shown.** Photos shows when a picture was taken and
 what took it, and no coordinates anywhere. Worth knowing, though: the
@@ -392,15 +407,32 @@ resume.
 
 ### Casting to a TV
 
-**The desktop and Android applications.** A film playing in the application can
-be sent to a cast-capable TV or dongle on the same network: *Cast to device* in
-the player, pick one from the list. On a phone, the film goes on playing silently
-on the phone while the TV shows it, and the screen can be turned off. While a
-TV plays the film, the player becomes its remote: the position shown is the
-TV's, with play/pause, 30-second jumps and a slider to go anywhere in the film.
-Devices appear as they answer, usually within a couple
-of seconds; the search carries on for a few more, for a TV that is still
-waking up.
+**The desktop and Android applications.** Films, photos and music can be sent
+to a cast-capable TV or dongle on the same network. The cast button is in the
+Videos and Music toolbars, at the top of Photos, in an album's bar, in the photo
+viewer and in the music bar — in a group and in Search alike — and *Cast to
+device* is in the video player. Devices appear as
+they answer, usually within a couple of seconds; the search carries on for a
+few more, for a TV that is still waking up.
+
+**A TV, once chosen, stays chosen** until *Stop casting*, from any cast button
+or from the player. Every film opened plays on it, and the player opens as its
+remote: the position shown is the TV's, with play/pause, 30-second jumps and a
+slider to go anywhere in the film. Every photo opened in the viewer is shown on
+it, and a slideshow pages the TV along with the screen. Choosing a TV from an
+album's bar opens its first photo. Music plays on it too, with the cover, title
+and artist on the screen: the music bar becomes its remote — play, pause, the
+slider, previous and next — and the queue moves on when the TV reaches the end
+of a track. Choosing the TV in the middle of a song carries it on there; *Stop
+casting* carries it on here. On a phone, a film goes on playing silently on the
+phone while the TV shows it, and the screen can be turned off, as it can while
+music plays on the TV.
+
+Photos are sent scaled to the TV's screen, upright, as an ordinary picture.
+The menus, covers and summaries stay on your phone or computer: the TV shows
+what is playing, not the application. It plays it in the TV's standard cast
+player, which shows its own name, *Default Media Receiver*, on the screen; a
+player of MeshBay's own is not built.
 
 The application decrypts the film and relays it to the TV itself, over your LAN.
 The TV is not a group member and holds no key — which is also why the relay's
@@ -974,13 +1006,15 @@ Better to know now than to go looking for it:
 - **The Android application is not released yet.** It works — groups, chat,
   films, downloads, casting — but is built and installed by hand and signed
   with a development key, so there is no store page and no update channel. The
-  back button and the lock screen do not drive it yet. A phone browser works
-  too.
+  back button and the lock screen do not drive it yet. Music keeps playing
+  with the screen off, from one track to the next, with a notification shown
+  while it plays. A phone browser works too.
 - **A node cannot be hosted on Android**, and is not planned to be.
 - **Hubs do not talk to each other yet.** Everyone in a group needs an account
   on the same hub.
 - **Casting reaches Chromecast devices** from the desktop and Android
-  applications. Support for other TV protocols is designed but not built.
+  applications, for films, photos and music. Support for other TV protocols is
+  designed but not built.
 - **Some subtitle tracks cannot be shown** — the ones stored as images rather
   than text, roughly one embedded track in five. Displaying them would need
   text recognition.