What does Advanced Artillery do in AoE3?

Ships 1 Mortar; Ships 3 Uhlan. The game says: "Ships 1 Mortar. Moves Horse Artillery and Mortars to the Fortress Age, +3 Uhlans."

Home City card

Advanced Artillery

Advanced Artillery (tech ID HCAdvancedArtilleryGerman) 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 1 Mortar; Ships 3 Uhlan. It hands over about 900 resources' worth.

Quick answers (3)

Which civilizations have the Advanced Artillery card?: Germans.
What does Advanced Artillery do in AoE3?: Ships 1 Mortar; Ships 3 Uhlan. The game says: "Ships 1 Mortar. Moves Horse Artillery and Mortars to the Fortress Age, +3 Uhlans."
What is the tech ID of Advanced Artillery?: HCAdvancedArtilleryGerman.

Ships 1 Mortar. Moves Horse Artillery and Mortars to the Fortress Age, +3 Uhlans.

What it does

Ships 1 Mortar(unit)
Ships 3 Uhlan(unit)

2 further effects (interface, visuals or AI) not listed.

What it hands over

1 × Mortar450 each
3 × Uhlan150 each

Total ≈ 900 resources — units at their train cost, crates and animals at what they hold.

Cost: 1
Sent from: III
Times it can be sent: 1
Game ID: HCAdvancedArtilleryGerman

In these decks

GermansIII×1

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