The subject may merit a brief explanatory note.

这题目也许要个简明的注释。

《新英汉大辞典》

Exhaustive circuit tourist map explanatory note.

详尽的线路导游图文字说明。

youdao

An added descriptive comment or explanatory note.

一种附加的描述性的解释或说明性注解。

youdao

Alongside the circular about the reward policy was also posted an explanatory note.

FORBES: China's Cities Take Steps To Stimulate Home Purchases

Links to other pizza companies, such as Pizza Hut and Papa John, would be added soon, said programmers Matt Burkinshaw and Riley Alexander in an explanatory note on the site.

BBC: Bitcoin virtual currency can now be used to pay for pizza