In Star Wars (vol. 1, Marvel) series that ran 1977 to 1986, there are a small handful of issues - all listed as the “A” version - that are incorrectly listed as Whitman Variants when they are in fact the earliest Direct Editions.
These are issues 23 through 32. You can tell by the fact the “diamond” in the top/left of the cover is different than the Whitman diamond - it is more of a rectangular diamond, while the Whitman diamond was perfectly square. Also, on these direct editions there is a barcode with a diagonal line through it. Whitman variants either had a blank UPC box, or just had a regular barcode. Marvel used this method for about a year before they started using the Spider-Man face (and later other images).
To the best of my knowledge - and I was buying these comics new as they came out, from a direct market comic shop - Whitman variants only went through issue 18 of this series.
Thanks,
- IVAN