After recalling the case-law on judicial notice of facts of common knowledge,[1] the Appeals Chamber held:

23. Whether a fact qualifies as a “fact of common knowledge” is a legal question.  By definition, it cannot turn on the evidence introduced in a particular case, and so the deferential standard of review ordinarily applied by the Appeals Chamber to the Trial Chamber’s assessment of and inferences from such evidence has no application. Mr. Nzirorera suggests that the Appeals Chamber should defer to the Trial Chamber’s discretion as to “admissibility of evidence” and “the manner in which facts are to be proven at trial”.[2] But the general rule that the Trial Chamber has discretion in those areas is superseded by the specific, mandatory language of Rule 94(A); as noted above, the Trial Chamber has no discretion to determine that a fact, although “of common knowledge”, must nonetheless be proven through evidence at trial.  For these reasons, a Trial Chamber’s decision whether to take judicial notice of a relevant[3] fact under Rule 94(A) is subject to de novo review on appeal.

30. Likewise, it is not relevant that these facts constitute elements of some of the crimes charged and that such elements must ordinarily be proven by the Prosecution.  There is no exception to Rule 94(A) for elements of offences.  Of course the Rule 94(A) mechanism sometimes will alleviate the Prosecution’s burden to introduce evidence proving certain aspects of its case.  As the Appeals Chamber explained in Semanza, however, it does not change the burden of proof, but simply provides another way for that burden to be met […]. (footnotes omitted).

See also para. 37.

See para. 25:

25. The Appeals Chamber has held that the basis on which judicial notice is taken pursuant to this sub-Rule is that the material is notorious.[1] Facts of common knowledge under Rule 94(A) of the Rules have been considered to encompass common or universally known facts, such as general facts of history, generally known geographical facts and the laws of nature, as well as those facts that are generally known within a tribunal’s territorial jurisdiction.[2] Once a Chamber deems a fact to be of common knowledge, it must also determine that the matter is not the subject of reasonable dispute.[3] […]