What mechanical effects impact a character's School Skills?

Question

In the Legends of the Five Rings core book, 4th Edition, page 134 (Book of Fire), emphasis mine:

SCHOOL SKILLS are the basic seven Skills taught to a character by his sensei while studying at his clan's School. These vary from School to School, and are specified in the write-ups for the individual Schools in this chapter. Various mechanical effects impact a character's School Skills.

However, I can't find in the Core Book any mention of these mechanical effects. No changes in rolling or raising in the Book of Earth, no changes to purchasing skills and progressing in the Book of Fire, no mention at all in the Book of Water.

What are the various mechanical effects that impact a character's School Skills, in the Core Book? Are there other such effects in official complement content?

Answer 1

Some School Techniques and Dis/Advantages use them, usually to give bonuses or penalties

Some Examples;

The Prodigy Advantage (P.152 of the core book)

Whenever you make a School Skill Roll, you gain a bonus of +1k0 to the roll

The Doubt Disadvantage (P.159)

Select one of your School Skills. Every time you use this Skill, you must declare one Raise that confers no benefit.

Or the Kasuga Smuggler IR 5 Technique (P.227)

A number of times per session equal to your Void Ring, you may gain a +5k0 bonus when making a roll with any of your School Skills.

There are several others scattered throughout the entire 4e library but the only general rule regarding them that applies to everyone that I can think of is if you ever get the opportunity to take a second basic school you must posses at least one rank in each of your new school's School Skills along with any emphases provided by the school.