[noun] + を除いて [noun] + を除いては [noun] + を除いた + [noun] [noun] + を除き (連用形, more formal/written) [noun] + を除けば (conditional form)
を除いて means "except for," "with the exception of," or "excluding." It is used to single out one or more items from a group and state that the rest of the group shares a certain characteristic or condition. The noun before をのぞいて除いて is the item being excluded.
The pattern is straightforward: Noun + を除いて + statement about the rest. The excluded item is marked with を, and のぞいて除いて is the te-form of the verb のぞく除く (to exclude/remove).
を除いて is fairly formal and is commonly found in written language, announcements, rules, and business contexts. There are several related forms:
を除いては – adds the topic particle は for slight emphasis on the exception:
を除き – a more concise written form (conjunctive form of 除く):
を除いた + Noun – used as a noun modifier:
Compare: たなか田中さんいがい以外、だれ誰もしらなかった知らなかった。 (same meaning, slightly more casual)