For wall installations your real concerns are whether you want to use thinset directly on the wood and whether you are using an exterior or interior type of plywood.
Can ceramic wall tile be installed over plywood.
Interior if you are working in an interior setting in a dry area where the tile will never come into contact with water you can install the tile directly onto the face of the plywood so long as you use the proper type of thinset.
Problems with ceramic directly on plywood or osb.
Installation of ceramic tile over plywood substrates with latex portland cement mortar.
While tile can be laid on plywood do not install tile directly onto the plywood subfloor itself.
You shouldn t do it.
Plywood and osb expand and contract with humidity and temperature much more than ceramic tile.
One question that folks new to ceramic tile frequently ask is whether they can lay the ceramic directly on top of a plywood or osb subfloor using a thinset cement or liquid nails to glue down the tile to the wood.
All wooden flooring when placed over conventional floor joist or other systems should be of a design and thickness so as to maintain a substrate deflection not to exceed 1 360th of span including live and dead loads.