How often did the European Parliament use its optional secret ballot rule?

Question

According to Wikipedia:

If at least 20% of the Parliament requests it before voting begins, the vote will be taken by secret ballot.

Citing (the 2nd para of) EP Rule 169, which is actually a bit more complex, for example, its first para says:

In the case of appointments, voting shall be by secret ballot without prejudice to Rules 13(1), 186(1) and 191(2), second subparagraph.

How often did the EP use this 20% rule [169(2)] to conduct a secret ballot, when one was not otherwise mandated (i.e. excluding appointment votes)?

Answer 1

I have found it extremely difficult to discover data on this. I can state with certainty that a secret ballot was not used between July 16th 2014 and February 25th 2016 (except with respect to appointments & term extensions) thanks to this dataset [1] which I was able to analyse.

The only reported use of the secret ballot rule (which has changed to EP Rule 180a in the 2019-2024 parliament) I can find, aside from elections, nominations, and term extensions, is the use during the session on January 31st 2019, where amendments to Parliament's Rules of Procedure were approved during a secret ballot initiated by members from the EPP group (full session minutes).

I also found articles suggesting that the EU's budget for 2014-20 would be voted on in a secret ballot, however, the results of votes for this session show that this did not take place.

I am forced to conclude given lack of evidence to the contrary, that the aforementioned vote on lobbyist transparency is the only previous use of this rule.

• [1] Cherepnalkoski, Darko; Karpf, Andreas; Mozetič, Igor and Grčar, Miha, 2016, Dataset of European Parliament roll-call votes and Twitter activities MEP 1.0, Slovenian language resource repository CLARIN.SI, http://hdl.handle.net/11356/1071.