[hipsterstal1n]

Ah yes, if there was documentation, it would specify that a Hilton key card should be used. Otherwise, a Hyatt or Westin key card being used may cause an incorrect check result of the door seal and cause possible loss of life.

[mannyv]

Well it should specify the thickness, length, and width of the keycard, since brands might change vendors

And of course it should specify which way it should be inserted.

And it needs to specify the amount of bend allowable given some amount of pressure. No point in using a bendy card.