The Bauhaus Cafe complements its retro-modern appearance by posting its phone number with a lettered prefix. This is a remnant of the early days of telephony, when local service was hard-wired into named "exchanges" of no more than 1,000 lines. Before the rotary dial was invented, callers were initially put through to an operator, who manually patched a switchboard to connect the caller to the number he or she verbally asked for. As phone use grew, exchanges grew and numbers got longer. The Seattle Times had the numbers over the years of "Main 300," "MAin 0300," "MAin 2-0300," and "622-0300," before the paper installed a new office phone system that required a block of separate numbers.