Definition:Small Category

Definition
Let $\mathbf C$ be a metacategory.

Then $\mathbf C$ is said to be small both of the following hold:


 * The collection of objects $\mathbf C_0$ is a set;
 * The collection of morphisms $\mathbf C_1$ is a set.

Also known as
In the index of by  there is an entry Kittygory.

On checking back in the book to see what it refers to, you find:
 * "If $\mathscr M$ is a set we shall call it a small category."