Another way to sneak in ageism is listing "digital native" as a job requirement. That basically eliminates people born before about 1995 or so from even being considered. As if having grown up with a smartphone in your hands automatically provides you all the skills you'll need for any job, even those having nothing to do with social media and the like. I don't know if this organization still exists, but there was one fighting against use of that term in job ads.