This is the 739th most frequent Finnish word.
koskevan
"Relating to" or "concerning."
In this sentence, 'koskevan' functions as a modifier specifying the topic of concern or interest.
Tämä kirja kertoo aiheesta koskevan ympäristönsuojelua.
This book discusses a topic concerning environmental protection.
Here, 'koskevan' is used to specify the subject matter the statement is referring to.
Annoin lausunnon koskevan uusia liikennesääntöjä.
I provided a statement concerning the new traffic rules.
In this case, 'koskevan' specifies the topic that the question is related to.