Hindi kaya R3 disks are only designated as "R3" to comply with the law but are actually mostly region free?
From my experience:
1. The OLDER (catalogue) Warner titles are usually Region-Free, but the newer blockbuster titles (especially those that come out on R3 ahead of R1 and have a different UPC number from the R1) are exclusively Region 3.
2.
Imported Magnavision (currently Php 695) titles are either locked to Region 3 or Region 3/4. The locally-pressed variants (Php 199, 299, 475) are usually Region-Free.
3. Viva's Fox/Disney titles (all imported) are locked to Region 3. Their other titles are Region-Free, but are also full screen and of very poor image/audio quality, so don't bother upscaling them with an HD DVD player... or even buying them in the first place.
4. C-Interactive titles are all Region-Free.