A number of issues may be raised concerning the validity of authorization cards. The potential significance is illustrated in Case VI-A . An employee is presumed to read and understand what he or she has signed. A signed authorization card can be used as evidence of majority support unless it is clear that the union stated that the only use for the card is to get an election. Cards must be signed and dated .
Cards are valid for purposes of a showing of interest for only one year.
The employer is not permitted to see the authorization cards, nor is the Board agent review of cards subject to challenge except in extreme circumstances . A showing of interest is required only in those cases initiated by a union or group of employees seeking certification, decertification or deauthorization. The employer, however, is under no obligation to petition for an election if a demand is made. The employer may simply refuse to recognize the union, leaving the burden on the union to initiate the petition. In AC and UC cases, no showing of interest is required because the union is already the representative of a certified unit and is seeking clarification of that unit or its certification.