South Korean officials have demanded a formal apology from the North and say they have not yet decided whether and how to pursue the matter further.

VOA: standard.2009.09.11

We haven't actually learned how to calculate the formal charge yet, we'll learn it soon.

实际上我们还没学如何计算形式电荷，我们很快就会学到了。

麻省理工公开课 - 化学原理课程节选

In a note today, CIBC World Markets analyst Mara Goldstein said the investigation is not yet a formal one, but could become one.

FORBES: SEC Probes Bristol-Myers

Their idea (not yet a formal proposal) has a certain poetry.

ECONOMIST: Global warming

If it had sought yet another formal investigation into all Microsoft's business practices, that could have lasted several years and even then failed to get any relief for Netscape until too late.

ECONOMIST: Microsoft��s browser