Marking on engine block? Engraved X

I recently got the car 2003, everything is fine, mechanic said everything is all good,and clean carfax.
What is with the chalked in X on the block, has anyone seen this before, or am I just being overly cautious?
X marks the spot.. might just be nothng
carfax sucks. . if u never report something .. carfax will never know.. i
know of places that repair a car ( body work) but if the body shop doesnt report the info or the owner doesnt report it.. carfax will never know. .
carfax sucks. . if u never report something .. carfax will never know.. i
know of places that repair a car ( body work) but if the body shop doesnt report the info or the owner doesnt report it.. carfax will never know. .



