I believe what Niels is referring to is the publication of what I believe is the exact same book or at least very close by Helm and Princeton in 2012 with differing names and one of them designated as second edition and the other not. So the current version is either “Birds of the Indian Subcontinent” from Grimmett, Inskipp, and Inskipp by Helm or “Birds of India: Pakistan, Nepal, Bangladesh, Bhutan, Sri Lanka, and the Maldives - Second Edition” from the same authors from Princeton.
So if Helm publishes a new edition as the second edition it won’t be the same as the Princeton second edition but perhaps would be the same as a presumably forthcoming Princeton third edition. Why not just get the jump on the bastards at Princeton and call yours the fourth edition

Or, perhaps better, coordinate to publish it under the same name this time and call them both third edition or 2025 edition or some such?