Local telephone numbers have always been subject to the constraint that the first digits must identify a geographic location, leaving less flexibility to select digits which spell specific phonewords. Toll-free numbering, as originally introduced by AT&T in 1967, was initially even more limited, as each geographic area code was hardwired to one or two specific exchanges in the +1-800 toll-free area code. This changed after Roy P. Weber of Bell Labs patented a "Data base communication call processing method" which laid the initial blueprint for construction of the SMS/800 database in 1982 and the portable RespOrg structure in 1993. A toll-free number, instead of indicating a geographic location, was merely a pointer to a database record; any number could geographically be reassigned anywhere and ported to any carrier. All seven digits were available to construct vanity numbers or phonewords.