How to deal with the missing information on vmrk file?

I'm conducting a psychological experiment using EEG. I'm analyzing EEG data with Psychotoolbox on MATLAB (not BrainVIsionAnalyzer) When I did preprocessing, I found 2 trials' data of "Position in data points" on vmrk file are missing as follows. (There should be MK116~121)

Mk112=Stimulus,S 4,4051572,1,0

Mk113=Stimulus,S 1,4127399,1,0

Mk114=Stimulus,S 2,4144879,1,0

Mk115=Stimulus,S 4,4164386,1,0

.

.

So I added like this,

Mk116=Stimulus,S 1,NaN,1,0

Mk117=Stimulus,S 2,NaN,1,0

Mk118=Stimulus,S 4,NaN,1,0

Mk119=Stimulus,S 1,NaN,1,0

Mk120=Stimulus,S 2,NaN,1,0

Mk121=Stimulus,S 4,NaN,1,0

But it didn't work.

How should I deal with the missing information?

Answer 1

[Walter Roberson]

https://pressrelease.brainproducts.com/markers/ describes the file format

There is no support for defining markers as existing but at some undefined point. If the marker does not have a specific position then it must not appear in the file.

If there are places in the file that have garbage signal but you know where, then use a Bad Interval marker.

If you paused recording, started a new experiment, or the like, and that is the reason for irregularities in the file then use a New Segment marker.