This is the 17743rd most frequent Russian word.
указанию
"Указанию" means "instruction" or "direction" in English.
In this sentence, 'указанию' (instruction) is used in the dative case to indicate the entity according to which the action is performed.
Действуй согласно указанию начальника.
Act according to the instruction of the supervisor.
Here, 'указанию' (instruction) is again in the dative case, used in a passive construct to indicate what received the priority.
Указанию был присвоен высокий приоритет.
The instruction was given high priority.
In this example, 'указанию' (instruction) reflects the directive from the ministry guiding the conduct of the training.