Convention for boundary in multipart requests
Multipart requests can have a convention of defining the boundaries between each part. This is typically done by starting with an empty string and then appending parts that are separated by some kind of delimiter, like a blank space or linefeed character. For example:

```text
POST /upload HTTP/1.1
Host: www.example.com
Content-Type: multipart/form-data; boundary=---------------------------8f7b6c0ae96d5
Content-Length:...


--8f7b6c0ae96d5
content of first part (the start)
-----------------------------8f7b6c0ae96d5
Content-Disposition: form-data; name="file"; filename=""

"some file data"

--8f7b6c0ae96d5
content of second part
----------------------------8f7b6c0ae96d5--
```
This way, it's clear what constitutes a new request body section when parsing the server response. The content-type header specifies `multipart/form-data` to indicate this type of message body, as well as all other relevant headers required for processing such messages on the receiving end.