The pair of longitudinal wide parallel bars are abrasion from the friction rollers that moved the card relative to the reader, and ejected the card on demand. The number (2564 in this example) is not a product code but a random code so that a specific card could be identified.
Image (and ruler) were scanned from a physical card on 2007-12-12.
{{Information |Description={{en|1=Magnetic card (c. 1980) as used in the IBM MC Selectric typewriter and [[en:IBM_Selectric_typewriter#Selectric_Composers|IBM MC Selectric Composer