Logic Behind the Order of Parts in Research Nodes?

[KiwiShark]

I can't seem to determine if there is any specific rhyme or reason behind the way parts are organized in the research nodes on the tech tree. It's not alphabetical, by size, by mass, or by part type. At least not consistently across all nodes.

For instance here's a few nodes that directly follow each other in Tier 3, [Part name (Size - Part Type)]:

Enlarged Power Systems: SP-XL "Gigantor" (MD - Solar Panel), FC-01 (XS - Converter), Z-1K (S - Battery)

Long-Range Generation: PB-NUK (XS - Generator), Z-4K (M - Battery), RA-100 (S - Transmitter), Communotron 88-88 (S - Transmitter), FCA-06 (S - Converter)

Nuclear Power: Z-375 (L - Battery), SP-XXL "Colossus" (L - Solar Panel), KR4-P3 (S - Converter)

They're all over the place! In some nodes there's fuel tanks followed by an engine and others an engine followed by fuel tanks. Generally  similar parts are grouped sensibly in individual nodes, although there are exceptions to even that. Medium Orbital Rockets has two pods, three other parts, a pod again, and one last other part.

If there's any formula to this I can't tell what it is. I wouldn't call this a bug because technically there isn't anything wrong, I don't know what the correct order would even be, it's just a weird quirk to the layout of parts in the nodes.

It would be nice to see some cohesion in the parts list for the nodes just for the heck of it, but I recognize this is about as pedantic as a suggestion gets.

[Superfluous J]

I would assume it's the internal part number, which likely is roughly in order of when the parts were added to the game.

But I don't know how to find that out.

[KiwiShark]

8 hours ago, Superfluous J said:

I would assume it's the internal part number, which likely is roughly in order of when the parts were added to the game.

But I don't know how to find that out.

Do they have a hidden id like that? That could be something, if they do.

[Superfluous J]

They pretty much have to. The parts are likely stored internally in a database and to correlate the tables together the most efficient way is with an id number.