Rules for Uppercase and lowercase for first letter

Hi all,

Are there any information in wiki or rules for using Uppercase or lowercase for first letter of a name?
For example,
**r**igidbody vs. **R**igidbody

if(!newCoconut.rigidbody) {
     newCoconut.AddComponent(Rigidbody);
}

(I am still very confused.)

Thanks in advance

In the scripting manual it states that upper case denotes a class or script name, while lower case denotes a variable.

hth