Certification is not a formality. It is the baseline that separates a genuine protective helmet from something that only looks the part. Any helmet worth wearing on the road should carry a current, verifiable certification.
A leather trimmed helmet needs a little more attention than a plain shell, but the upkeep is straightforward. Dust and light dirt can be wiped away with a soft, dry cloth, Epicurist and any marks are best treated with a product made for leather rather than general household cleaners, which can dry the material out over time.
A certified helmet carries a label inside the shell showing the standard it meets, along with a homologation number that identifies the specific model tested. This label is worth checking on any helmet, since it confirms the exact helmet in your hands passed the test, not just the range it belongs to.
Neither format is a universal answer. Weather, speed, journey length and personal comfort all play a part, and many riders end up owning one of each for different trips.
The liner deserves the same care. A removable, washable liner keeps the inside fresh, and following the maker's washing instructions protects both the padding and the stitching around it.
Trying a helmet on in person, and wearing it for a few minutes rather than a few seconds, catches problems a size chart alone cannot. Padding also settles slightly with use, so a helmet that feels snug when new is usually the right call.