This is the 401st most frequent Slovak word.
oficiálne
Officially.
In this context, "oficiálne" is an adjective describing the noun "pravidlá" (rules).
Oficiálne pravidlá platia pre všetkých účastníkov.
The official rules apply to all participants.
The word "oficiálne" functions as an adverb explaining how the comment will be made.
Oficiálne sa o tejto zmene vyjadria zajtra.
They will officially comment on this change tomorrow.
Here, "oficiálne" is used as an adverb to describe the manner in which the document was approved.