Explain that tick spacing affects which ticks can be initialized in t…

…he ticks bitmap (#75)

content/docs/milestone_2/tick-bitmap-index.md

@@ -93,7 +93,8 @@ function flipTick(
 }
 ```
 
-> Until later in the book, `tickSpacing` is always 1.
+> Until later in the book, `tickSpacing` is always 1. Please keep in mind that this value affects which ticks can be initialized: when it
+equals 1, all ticks can be flipped; when it's set to a different value, only ticks divisible by the value can be flipped.
 
 After finding word and bit positions, we need to make a mask. A mask is a number that has a single 1 flag set at the
 bit position of the tick. To find the mask, we simply calculate `2**bit_pos` (equivalent of `1 << bit_pos`):

content/docs/milestone_4/factory-contract.md

@@ -94,7 +94,9 @@ Thus, each pool is uniquely identified by this set of parameters:
 Factory contract uses this set of parameters as a unique identifier of a pool and passes it as a salt to generate a new
 pool contract address.
 
-> From now on, we'll assume the tick spacing of 60 for all our pools, and we'll use 10 for stablecoin pairs.
+> From now on, we'll assume the tick spacing of 60 for all our pools, and we'll use 10 for stablecoin pairs. Please notice
+that only ticks divisible by these values can be flagged as initialized in the ticks bitmap. For example, only ticks -120,
+-60, 0, 60, 120, etc. can be initialized and used in liquidity ranges when tick spacing is 60.
 
 ## Factory Implementation