首先,SSB has {USB, LSB},然后有个好玩的地方:
LoTW 的 术语说明中有提到,对于 QSO 的 Confirmation,需要满足一条:
both QSO descriptions specify the same mode (an exact mode match), or must specify modes belonging to the same mode group
精确模式匹配(Exact mode match)自然不用多说,而同组模式匹配(same mode group)中,有意思的地方就来了。
除了前面回复提到的 USB/LSB 都属于 SSB 的子模式外,AM/FM/SSB 又都属于话音(Phone)大分组,也就是说甚至一方提交 SSB 的日志,另一方提交 FM 的日志,也可以形成 QSO。
Mode Group -- a collection of similar modes. The Phone mode group, for example, includes the modes AM, FM, and SSB. Other mode groups include CW, Data, and Image.

TQSL中的模式定义
当然 LoTW 也特别强调了 Some WAS awards require a confirmation with an exact mode match,因此虽然存在粗放匹配的可能,也应尽量提交精确模式的日志。
QRZ.com则是有如下文档:
Note that in the case of confirmations, "Mode" is the primary mode. Submodes are considered their parent mode for the cases of confirmation. For example, wherein all other details match accordingly, one operator logging SSB as a mode will match another operator logging the QSO as USB (or LSB).
同样支持 SSB 的子模式匹配。