And it is very, very short, starting and ending with the SoftBank 008Z. The 008Z is the only phone that SBM currently will unlock. As I've been expecting, the only phones that Docomo isn't going to hit with a FOMA tethering fee are going to be limited to handsets unlocked by other domestic carriers.
I ran across this while researching a post (briefly outlined on g+), the gist of which is avoiding FOMA tethering fees by using a Xi SIM.
Searching the Docomo site for SIM cards to see if there is any mention of selling Xi SIMs (there isn't), I noticed the following addition:
ただし、他社携帯電話機がテザリング非対応であることなどを当社で確認できた電話機については、当電話機に当社指定のアクセスポイントを設定いただくことで、設定後のパケット通信に関して、スマートフォン定額通信の定額料・上限額が適用されます。当該電話機については、当社で他社携帯電話機がテザリング非対応であることを確認が取れた時点で、当社ホームページにてお知らせします。現時点での対象は以下のとおりです。This is explaining that handsets which have been confirmed to lack tethering functionality will be charged the standard smartphone rate without a tethering fee. It goes on to further specify that the first 8 digits of the "serial number" must be 35732604. This is interesting. In this case, is serial number referring to IMEI? If so, did Docomo already register the IMEIs of the SBM 008Z phones in its database, thereby allowing connection to the biz houdai APN (which is IMEI restricted)?
EDIT: Actually, I think the Xi SIM cards are what the ドコモUIMカード is referring to.