This excerpt taken from the VRSN 10-K filed Jul 12, 2007.
3.3.1 Transfer Pending Period
The Transfer Pending Period is a specified number of calendar days following a request from a registrar (registrar A) to transfer a domain in which the current registrar of the domain (registrar B) may explicitly approve or reject the transfer request. The current value of the Transfer Pending Period is five calendar days for all registrars. The transfer will be finalized upon receipt of explicit approval or rejection from the current registrar (registrar B). If the current registrar (registrar B) does not explicitly approve or reject the request initiated by registrar A, the registry will approve the request automatically after the end of the Transfer Pending Period. During the Transfer Pending Period:
a. RRP or EPP TRANSFER request or RRP or EPP RENEW request is denied.
b. SYNC is not allowed.
c. RRP DEL or EPP DELETE request is denied.
d. Bulk Transfer operations are allowed.
e. RRP MOD or EPP UPDATE request is denied.
After a transfer of a domain, the RRP or EPP TRANSFER request may be denied for 60 days.