Writing IPTC in Canon CR2 RAW

[BuckSkin]

I have been using ExifToolGUI successfully for ages writing GPS and various fields into RAW files.

A few minutes ago, just to see what would happen, I used the XnView IPTC Editor to write one of my templates into a test CR2 RAW file.

It took a couple seconds longer for it to do it's thing as compared to writing to a jpeg; however, it seems to have worked.

I can see/read the IPTC in XnView and I can also view it in ExifToolGUI.

The information is contained within the file; no sidecar.

I have not yet created a jpeg from the RAW file to check the outcome.

I have searched this and am more confused after searching than I was before.

Is it okay practice to write IPTC, XMP, and Keyword Tags into RAW files ?
Will it corrupt the picture data?

Thanks.

[xnview]

which settings>Metadata do you use?

[BuckSkin]

which settings>Metadata do you use?

[xnview]

yes in this case IPTC & XMP can be written, but there is a limitation, currently IPTC from RAW can't be extracted. And a bug to extract XMP from RAW