Pushing

From OGame Wiki

Pushing is defined as a lower ranked player sending resources to a higher ranked player without return service. This is a bannable offense and the Game Operators often check logs and ban both the person sending the res to higher ranked player (the pusher) and the player who received the resources (the pushed).

Trading with a player ranked higher than you is permissible, but the trade must be completed within 24 hours of the first delivery of the trade unless the GO has given permission first.

If a player within the alliance is crashed, and other players ranked lower than him wish to send the crashed player resources, a Game Operator can be asked for permission to send resources up to the total units lost.

Sending resources to a higher ranked player is also permissible when it's for a service such as a "loaned phalanx" or a "headhunt" as long as the game operator is notified first and grants permission.

Higher ranked players are always allowed to push ("pull") lower ranked players up.