[BUG] Unifomize boilerplates about sharing original data under `/sourcedata`

[oesteban]

Describe your problem in detail.

From @Remi-Gau's proposal in #1128 (comment):

How about we remove this phrase from this BEP and open a separate PR to also remove similar sentences from other data types and make sure it is expressed only once in the common principles in way we all agree on?

We have done similar "refactoring" in the past when we started noticing duplication / divergence across datatypes.

This conversation was initiated from some boilerplate regarding /sourcedata in the context of #1128 (https://github.com/bids-standard/bids-specification/pull/1128/files#r1411290644).

Describe what you expected.

No response

BIDS specification section

@robertoostenveld cited several instances where these statements are found along the specs (https://github.com/bids-standard/bids-specification/pull/1128/files#r1412100006).

[effigies]

I think this is already covered extensively in common principles:

https://github.com/bids-standard/bids-specification/blob/5b835b0b182b50aa27ead6dffeb727e59322d1fe/src/common-principles.md?plain=1#L241-L260

As well as:

https://github.com/bids-standard/bids-specification/blob/5b835b0b182b50aa27ead6dffeb727e59322d1fe/src/common-principles.md?plain=1#L125-L134

This macro renders a list, including:

• sourcedata: A directory where to store data before harmonization, reconstruction, and/or file format conversion (for example, E-Prime event logs or DICOM files). See the relevant section for more information.

I vote for simple removal of this language from the modality-specific pages.

[oesteban]

Yup, that was the position I tried to explain in the context of BEP020 and I believe what @Remi-Gau proposed in more practical/precise terms at the end.

[effigies]

Okay. I thought there was a suggestion that we need to add language to common principles.

[oesteban]

I think the proposal is more like we make sure nothing relevant is lost at all if the language is removed from modality-specific files and update the common principles before removal if some detail is found to be important.