The phrase "although classified" is correct and usable in written English.
It can be used to introduce a contrast or exception regarding something that is classified, often in discussions about information or documents.
Example: "Although classified, some details of the project were leaked to the public."
Alternatives: "even though it's classified" or "despite being classified".
Although classified in the same order as shrews (family Soricidae), solenodons are only distantly related to them and do not have any close living relatives.
Although classified as a carnivore, the raccoon is omnivorous, feeding on crayfish and other arthropods, rodents, frogs, and fruit and other plant matter, including crops.
Acts contributing to the actual treatment of the body after burial, although classified under the general label of secondary treatment of the deceased, have only recently started a fruitful discussion regarding the different stages of mortuary complexity.
Although classified as a large value fund, GW& K combines value plays, defined as attractive businesses that sell at discounted price-to-earnings or price-to-book multiples to the Standard & Poor's 500, with growth companies, those with rising earnings or sales.
Although classified as an australopithecine, the creatures were partly ape, with a tiny brain, long arms, a chimp-sized body, and a narrow birth canal.
Although classified as a Mall REIT, Tanger Factory Outlets (SKT) has also been beaten down by Mr. Market, even though the Greensboro-based REIT owns no department stores whatsoever.
Refugees have different legal rights than economic migrants, although classifying people into these two categories can be difficult in practice.
Although classifying a protein as a contaminant necessarily makes assumptions about the requirements for PD function, we judged that proteins from plastids, mitochondria, nuclei and some classes of cytoplasmic proteins would qualify.
Although classifying drugs as replicating- and/or nonreplicating-active compounds is often straightforward (Fig. 2), for some drugs, further classification of a replicating-active compound as bacteriostatic or bactericidal requires careful analysis of CARA results.
Edward Albee, although often classified as one of the movement, also writes about urban realities rather than private nightmares.
Writing about the current production directed by Ian Rickson, Mr. Isherwood writes that "although Chekhov classified 'The Seagull' as a comedy," the production "strikes a consistently bleak note".
