What does Yankton Support do in AoE3?

Ships 6 Rifle Rider; Rifle Rider: damage +20%. The game says: "The Yankton council sends 6 Rifle Riders and increases the attack of all Rifle Riders."

Home City card

Yankton Support

Yankton Support (tech ID HCXPSiouxYanktonSupport) is a Home City card in AoE3: Definitive Edition 100.19.18309, in the decks of 1 civilization, sent from the Fortress Age. Effect: Ships 6 Rifle Rider; Rifle Rider: damage +20%. It hands over about 1,260 resources' worth.

Quick answers (3)

Which civilizations have the Yankton Support card?: Lakota.
What does Yankton Support do in AoE3?: Ships 6 Rifle Rider; Rifle Rider: damage +20%. The game says: "The Yankton council sends 6 Rifle Riders and increases the attack of all Rifle Riders."
What is the tech ID of Yankton Support?: HCXPSiouxYanktonSupport.

The Yankton council sends 6 Rifle Riders and increases the attack of all Rifle Riders.

What it does

Ships 6 Rifle Rider(unit)
Rifle Rider: damage +20%

What it hands over

6 × Rifle Rider210 each

Total ≈ 1,260 resources — units at their train cost, crates and animals at what they hold.

Cost: 1,0001
Sent from: III
Times it can be sent: 1
Game ID: HCXPSiouxYanktonSupport

In these decks

LakotaIII×1

Source: techtreey.xml and the Home City files, AoE3: DE 100.19.18309 (build 25040513).