However, the text makes no mention of an ability to move orthogonally sideways.

In a non-capturing move, pieces can move orthogonally one space per turn.

A rook moves orthogonally any number of points in a straight line.

As a flying gold cannon it may move orthogonally over whole rows and is able to leap one piece while moving.

It may therefore move orthogonally over whole rows and is able to leap one piece while moving.

Because it cannot move orthogonally or backward, a stone general can only reach less than half the squares on the board.

Because it cannot move orthogonally, a bishop can only reach half the squares on the board.

When a piece has a red side showing it moves orthogonally (or straight).

When a piece has a blank side showing it can move either diagonally or orthogonally.

The guards can move orthogonally or diagonally one space at a time onto an empty point.