Terrain marker

A Terrain marker is an object used to mark a location on the terrain. Generally, it is placed by using an item to spawn the object, but could be placed by a spell or an ability.

Any placeable object can mark terrain, but in order to be useful the marking object must be:

• Visible over a distance - in WoW, that generally means a large object
• If subtlety is warranted, a small object may server better
• Persistent - no fixed duration, but generally at least tens of seconds or several minutes
• Stays in a fixed location - if it wanders, it can't mark a spot on the map

• Smoke Flares are the quintessential example. The Smoke Flare pyrotechnic device places a smoke column on the terrain.
• White Smoke Flare
• Green Smoke Flare
• Purple Smoke Flare
• Red Smoke Flare
• Cannoneer's Smoke Flare (blue, Horde quest item)

• Lunar Festival terrain markers. These two stones create a column of light on the terrain.
• Elder's Moonstone
• Elune Stone

• Ad Hoc, generally smaller objects. Anything that can be placed; examples:
• A campfire, placed by using the Basic Campfire skill.
• A keg of Brewfest Brew, placed by using a Brewfest Pony Keg (not consumed) - if you have the item, the use is free
• Summoning a Snowman companion (requires and consumes a Snowball)
• A Portal, summoned by a mage. It doesn't matter where the portal goes, it is being used for its graphic property in the game environment (requires and consumes a Rune of Portals (original))

Some uses that people have come up with:

• marking locations for raids
• smoke bomb the Flag Rooms in the Warsong Gulch battleground
• props for floor shows and fashion shows

Where each of these can be placed varies. The Snowman companion is versatile in that regard, but be aware that companions despawn when a ship or a zeppelin crosses into a new zone.