You have actually posted two separate terms, representing two distinct special handling services offered by Japan Post.

1. The first is 特定記録, which is a fairly new service. The Japan Post website translates it as "Acceptance-recorded mail," which I dislike, but it is what it is. See the two references below:

http://www.post.japanpost.jp/english/service/domestic_ms.htm...
"Acceptance-recorded mail ("Tokutei kiroku yubin"): This service is intended only to record acceptance of mail. No compensation for damaged or lost mail is provided."

http://www.post.japanpost.jp/lpo/tokutei/
[Below the explanation of the new service in Japanese, you will see a fee chart that confirms that there is no such thing as 特定記録書留 as a combined service.]

2. The second is 書留, which translates to "registered mail," as you probably already know.

http://www.post.japanpost.jp/english/service/domestic_ms.htm...
"Registered Mail ("Kakitome"): With registered mail, the entire delivery process from acceptance of mail at the counter to delivery to the addressee is recorded. In the event registered mail is damaged or lost while being handled by the post office, you will be indemnified for the amount of actual loss within the limit of the claimable amount of indemnity declared (Japanese yen; the same applies to the following). The maximum for this is 500,000 yen for cash contents and 5,000,000 yen for items other than cash. If no declaration has been made, indemnity will be made for the actual loss within the limit of 10,000 yen for cash content and 100,000 yen for items other than cash.

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Note added at 56 mins (2011-01-10 01:36:00 GMT)
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Just for comparison, the USPS equivalent of 特定記録 seems to be Certificate of Mailing. I personally think that the USPS service is better-named, but you should probably stick with the unwieldy "Acceptance-recorded mail" if your document is discussing the Japanese postal system. http://www.usps.com/send/waystosendmail/extraservices/certif...