A document reportedly meant for employees of Japanese telecom KDDI's "au" wireless service has been leaked, showing the carrier will begin taking preorders for Apple's iPhone 5S on June 20 ahead of a launch in July.

Obtained by French website Nowhereelse.fr., the supposed document looks to be meant for sales floor staff and carries pricing information as well as a few details regarding the as-yet-unannounced iPhone 5S.

While AppleInsider cannot vouch for the document's authenticity, the laminated paper is very similar to the current product and pricing "cheat sheets" referred to by many cell phone dealers and official carrier stores in Japan. It should be noted, however, that the cards can easily be reproduced as some are printed directly at point of sale from a PDF file, with the only distinguishing feature being a company logo.

Written and starred in red is information for the iPhone 5S "new product," which is scheduled for a pre-sale announcement date of June 20 with sales starting in July. Below the release dates is a notation for major feature changes from the iPhone 5, which in this case says the supposed 5S will carry a fingerprint reader, 13-megapixel camera and iOS 7.

The areas highlighted in green offer information regarding au's current monthly plans for the iPhone 5, including LTE flat rate plans and family calling subscription options, as well as a cash back bundle offer for users of the telecom's "hikari" home internet service.

While mere speculation, the information quoted in the purportedly leaked material does jibe with the timeline of Apple's upcoming Worldwide Developers Conference, which is scheduled to take place from June 10 through 14. If the iPhone 5S were to be announced at the conference, it would be one week prior to the June 20 pre-sale date referred to in the supposed KDDI document.