The context is that of a discussion about substance. Veṅkaṭanātha feels the need to respond to the (no longer actual) criticisms of some Buddhist opponents from long ago and tries to establish the persistence of substance through time on the basis of the fact that we can, for instance, touch what we had previously seen, a phenomenon which would be unexplainable if one were to seize only qualia without substrate. The Buddhist point of view is presented as the pūrvapakṣa one needs to defeat:

evam āhur vaibhāṣikāḥ—

nirādhārā nirdharmakāś ca rūpādayaś catvāraḥ padārthāḥ. te cakṣurādyekaikendriyagrāhyāḥ iti. (SS ad TMK 1.8)

So said the Vaibhāṣikas:

“The categories are four, beginning with the visible, [and] they are without support and without characteristics. They are perceivable by only one sense-faculty [respectively], beginning with the sight (for the visible) and so on.”

This is somewhat surprising, since I do not know of Vaibhāṣikas upholding the existence of four instead of five skandhas. Anyway, the reference to rūpa makes one think of the group rūpa-vedanā-saṃjñā-saṃskāra-vijñāna, perhaps in the form of the classification rūpa-citta-caitta-cittaviprayukta found in Vasubandhu’s AKBh.

Immediately thereafter, however, comes the verse about Vātsīputrīyas, which reads as follows:

vātsīputrās tu śabdādīn pañca vaibhāṣikā viduḥ |

śabdātmānaś caturṣv eva kecid ity apare ‘bruvan ||

Here, the reference to śabda brings one back to śabda-sparśa-gandha-rasa-rūpa classification.

I am not sure I can translate the verse correctly, but due to the preceding one, I would try something like:

Others say, by contrast, that the Vātsīputra Vaibhāṣikas know five [categories] beginning with śabda [and] that [these categories] consist in śabda [etc.], instead of only four [categories] (as maintained above).

Does it mean that the Vatsīputrīyas recognised the substances usually acknowledged in “Hindu” systems?