RFC1867 was updated by RFC2388

docs/libcurl/libcurl-tutorial.3

@@ -502,13 +502,14 @@ then passing that list to libcurl.
 While the simple examples above cover the majority of all cases where HTTP
 POST operations are required, they don't do multi-part formposts. Multi-part
 formposts were introduced as a better way to post (possibly large) binary data
-and were first documented in the RFC1867. They're called multi-part because
-they're built by a chain of parts, each being a single unit. Each part has its
-own name and contents. You can in fact create and post a multi-part formpost
-with the regular libcurl POST support described above, but that would require
-that you build a formpost yourself and provide to libcurl. To make that
-easier, libcurl provides \fIcurl_formadd(3)\fP. Using this function, you add
-parts to the form. When you're done adding parts, you post the whole form.
+and were first documented in the RFC1867 (updated in RFC2388). They're called
+multi-part because they're built by a chain of parts, each part being a single
+unit of data. Each part has its own name and contents. You can in fact create
+and post a multi-part formpost with the regular libcurl POST support described
+above, but that would require that you build a formpost yourself and provide
+to libcurl. To make that easier, libcurl provides \fIcurl_formadd(3)\fP. Using
+this function, you add parts to the form. When you're done adding parts, you
+post the whole form.
 
 The following example sets two simple text parts with plain textual contents,
 and then a file with binary contents and uploads the whole thing.