SN55LVDS31-SP: Does skew specification cover like-to-like and like-to-unlike edges?

I'm trying to verify timing on a project with the SN55LVDS31, however Tsko is somewhat ambiguous. I need to know if the channel-to-channel skew is defined only for like-to-like edges or if it also covers like-to-unlike edges as well. If not, can it be safely assumed that Tplh and Tphl track, as in one will not be at the minimum specification within a component at the same time the other is at a maximum?

The similar SN65xxx section of the non-SP datasheet (https://www.ti.com/lit/ds/slls261n/slls261n.pdf) has a note for Tsko explicitly stating skew only for same direction, but there is no such indication for the SN55xxx IC in the -SP or non-SP datasheet.

Thank you for any help.