"BlackRock's six-digit numeric code (340965) is notably less circulated in public forums than three-letter ticker codes, slightly reducing discovery risk. However, finance-sector codes in NYC and SF see elevated scrutiny. "Medium-risk codes are subject to spot checks, especially during mid-week peak business travel, with properties in major metropolitan areas being the most likely to ask for a badge." BlackRock's NYC concentration and premium rate level keep this firmly at Medium. Numeric codes also trigger less "code sharing" behavior, reducing overall exposure volume."

"My last couple of corporate RFID cards had no company name on them for security purposes. My current company doesn’t do business cards. I use my Bonvoy card for corporate travel to get the points. I’d have to write them an email standing at the check in desk, I guess."

"I now always make it a matter of course to carry documents (business cards of my contacts, e-mails requesting my visit etc.) from my host company when I travel. This has always proven sufficient for the few times I've been challenged by the front desk clerk."