Fixes #64 - changes 1.12 to say that it is RECOMMENDED for Publishers to...

README.md

@@ -84,7 +84,7 @@ public interface Publisher<T> {
 | 7      | Once a terminal state has been signaled (`onError`, `onComplete`) it is REQUIRED that no further signals occur. Situational scenario MAY apply [see 2.13] |
 | 9      | `Subscription`'s which have been canceled SHOULD NOT receive subsequent `onError` or `onComplete` signals, but implementations will not be able to strictly guarantee this in all cases due to the intrinsic race condition between actions taken concurrently by `Publisher` and `Subscriber` |
 | 10     | `Publisher.subscribe` SHOULD NOT throw a non-fatal  `Throwable`. The only legal way to signal failure (or reject a `Subscription`) is via the `onError` method. Non-fatal `Throwable` excludes any non-recoverable exception by the application (e.g. OutOfMemory) |
-| 12     | `Publisher.subscribe` MAY be called as many times as wanted but MUST be with a different `Subscriber` each time [see 2.12]. It MUST reject the `Subscription` with a `java.lang.IllegalStateException` if the same `Subscriber` already has an active `Subscription` with this `Publisher`. The cause message MUST include a reference to this rule and/or quote the full rule |
+| 12     | `Publisher.subscribe` MAY be called as many times as wanted but MUST be with a different `Subscriber` each time [see 2.12]. It is RECOMMENDED to reject the `Subscription` with a `java.lang.IllegalStateException` if the same `Subscriber` already has an active `Subscription` with this `Publisher`. The cause message MUST include a reference to this rule and/or quote the full rule |
 | 13     | A `Publisher` MAY support multi-subscribe and choose whether each `Subscription` is unicast or multicast |
 | 14     | A `Publisher` MAY reject calls to its `subscribe` method if it is unable or unwilling to serve them [1]. If rejecting it MUST do this by calling `onError` on the `Subscriber` passed to `Publisher.subscribe` instead of calling `onSubscribe`" |
 | 15     | A `Publisher` in `completed` state MUST NOT call `onSubscribe` and MUST signal errors using `onError` for the corresponding `Subscriber` |