A better understanding of Strongholds

In release 9.2 Strongholds was added to World of Tanks. Strongholds is a game mode available to clans and limited to members of the same clan. Strongholds enables clans to build structures using the "Industrial Resource". In release 9.2 structures built in strongholds can be leveled up from 1 to 4 and will each provide a different benefit to the clan. In future releases structures will be able to reach level 10. The type of structure will determine the benefit to the clan and the level of the structure will determine the amount of that benefit.
Strongholds is planned to have 3 battle modes however the introduction of Strongholds in 9.2 consists of only the Skirmish mode. Similar to Tank Companies, clans that wish to participate in skirmishes will select a level of a skirmish battle (Medium, Champion, or Absolute). Medium will include tiers 1-6, Champion will include tiers 1-8, and Absolute will allow all tiers from 1-10.
Clans will form up a detatchment of up to 7 tanks for Medium, 10 tanks for Champion, and 15 tanks for Absolutes. Once formed the leader of the detatchment will enter a battle queue. They will fight a randomly matched team from that queue. Currently there is no matchmaking component.
Each Skirmish battle will provide your clan with the Strongholds currency, known as "Industrial Resource". When you build up this resource, clans can develop "Reserves", which are basically boosts to your earnings in all types of battles (including random battles). Industrial Resource also allows you to level up your structures, which makes your Reserves give you bigger boosts. You can use the Reserves whenever your clan decides will be most beneficial to you. To see a full list of the Reserves that are available, see this page (about 2/3 of the way down). Only one reserve can be used at a time and once triggered the benefit will last 2 hours.
The following is a list of how clan roles apply to Strongholds:

Commander - Create/Delete Stronghold, Manage Clan Settings (such as time for defending one's own Stronghold), + everything below

Dep Comm - Open/Close a "Zone" (each road), build structures, manage Reserves, Attack enemy Strongholds, + everything below

Field Comm - Manage Skirmish teams, + everything below

All others - Ability to choose which structure their share of battle earnings apply to, create Skirmish teams, view information about your own clan's stronghold

Here is a list of Structures and the bonuses they can provide.

Structure	Reserves	Bonus Type	Maximum Value*
Financial Unit	Battle Payments	Increased earnings for all battles (Credits)	Up to 50%
Tankodrome	Tactical Training	Increased earnings for all battles (XP)	Up to 50%
Military School	Military Maneuvers	Increased earnings for all battles (Free XP)	Up to 50%
Training Unit	Additional Briefing	Increased earnings for all battles (Crew XP)	Up to 100%
Transportation Unit	High-Capacity Transport	Increased earnings for all Skirmishes (Industrial Resources)	Up to 100%

In a future release Strongholds will be able to reach levels 5-10 and will open the Attack and Defense battle options in the Strongholds game mode. If a Stronghold is upgraded to level 5 other clans will be able to utilize the Attack battle option to target the Stronghold. The clan owning the Stronghold will have a preset Stronghold defense time window and will need to defend it from attack during that window. The effects a successful raid or a failed defense is still being determined.