Now you know that whenever you need them you can use them in **FastAPI**.

### Pydantic v1 `regex` instead of `pattern` { #pydantic-v1-regex-instead-of-pattern }

Before Pydantic version 2 and before FastAPI 0.100.0, the parameter was called `regex` instead of `pattern`, but it's now deprecated.

You could still see some code using it:

//// tab | Pydantic v1

    /** Order of name resolution methods to use */
    protected List<ResolverType> resolverOrder;
    /** Maximum buffer size for IO operations */
    protected int maximumBufferSize = 0x10000;
    /** Maximum buffer size for SMB transaction operations */
    protected int transactionBufferSize = 0xFFFF - 512;
    /** Number of buffers to keep in cache */
    protected int bufferCacheSize = 16;

* 🌐 Add Korean translation for `/docs/ko/docs/tutorial/body.md`. PR [#11000](https://github.com/tiangolo/fastapi/pull/11000) by [@KaniKim](https://github.com/KaniKim).