NOTATIO

This, from the first movement of Brahms' 4th Symphony, is 100% clear, but I think probably unusual in its vertical alignment - at least I don't remember seeing it notated exactly like this elsewhere.

Any thoughts?

I would probably have written that on two separate staves … In any case a large symphony orchestra's 2nd violin section of 12 or 14 players might avoid double stopping altogether and prefer to div a 4.

The reason is voicing. The whole notes are having invisible stems. The voice 2 is down-stemed placed on the right.

David Ward wrote:I would probably have written that on two separate staves … In any case a large symphony orchestra's 2nd violin section of 12 or 14 players might avoid double stopping altogether and prefer to div a 4.

I think it is rather a vertical spacing issue. 4 staves would make the score much higher, and therefore some pages longer. At this place, dividing in 4 is absolutely not needed. Orchestra musicians are very experienced in this.
The early 1900 scores (and late 1800) are very effective in spacing and divising. Some Strauss scores are so compact, it is unbelievable how the engravers achieved this.
French scores, particularly Debussy and Ravel, have setup of divided violins in two, not always needed.

BTW I played this symphony, as Vn1.

For what it is worth, I am pretty sure that I have seen this elsewhere. I agree with OCTO. that Brahms was too frugal to lay it out on two staves when one works well enough.

While players often divide up double stops, Brahms might not have been pleased if it were done here: it is an intimate moment. And the double stops continue like this for several more measures, all of them carefully laid out as double stops.

The double stems on the divisi pizz. notes in the first measure, which ends a similar 8 measure passage, is also interesting.

David's example is from the Brahms Complete Works. Here is the original edition, which uses a different notation:

Yes, I’ve seen this kind of alignment elsewhere too. Note the brackets indicating double-stops (vertical slur-shapes in the Complete Works edition). I checked the part at IMSLP and it’s the same as the score, no extra staff needed: