How strict is the checker? Is punctuation and spaces necessary? And, perhaps, if one recognized the source but was too lazy to figure out the rest, must diacritics (eg è) be removed?
Punctuation/spaces are not necessary. The checker will automatically convert your message to uppercase and strip it of non-alphabetical characters, then compare it against the answer. Diacritics will also be automatically removed from the message. But don't worry about diacritics for now... you won't need them till the later challenges.
By non-alphabetical, is this limited to the Latin alphabet? Would Cyrillic's А and Greek's Α be considered identical to Latin's A?
How strict is the checker? Is punctuation and spaces necessary? And, perhaps, if one recognized the source but was too lazy to figure out the rest, must diacritics (eg è) be removed?