1 files changed, 16 insertions, 4 deletions

diff --git a/01.md b/01.md
index 0cf03ed..ecac6f6 100644
--- a/01.md
+++ b/01.md
@@ -29,7 +29,7 @@ The only object type that exists is the `event`, which has the following format
 }
 ```
 
-To obtain the `event.id`, we `sha256` the serialized event. The serialization is done over the UTF-8 JSON-serialized string (with no white space or line breaks between the fields) of the following structure:
+To obtain the `event.id`, we `sha256` the serialized event. The serialization is done over the UTF-8 JSON-serialized string (which is described below) of the following structure:
 
 ```
 [
@@ -42,6 +42,18 @@ To obtain the `event.id`, we `sha256` the serialized event. The serialization is
 ]
 ```
 
+To prevent implementation differences from creating a different event ID for the same event, the following rules MUST be followed while serializing:
+- No whitespace, line breaks or other unnecessary formatting should be included in the output JSON.
+- No characters except the following should be escaped, and instead should be included verbatim:
+  - A line break, `0x0A`, as `\n`
+  - A double quote, `0x22`, as `\"`
+  - A backslash, `0x5C`, as `\\`
+  - A carriage return, `0x0D`, as `\r`
+  - A tab character, `0x09`, as `\t`
+  - A backspace, `0x08`, as `\b`
+  - A form feed, `0x0C`, as `\f`
+- UTF-8 should be used for encoding.
+
 ### Tags
 
 Each tag is an array of strings of arbitrary size, with some conventions around them. Take a look at the example below:
@@ -101,12 +113,12 @@ Relays expose a websocket endpoint to which clients can connect. Clients SHOULD
 Clients can send 3 types of messages, which must be JSON arrays, according to the following patterns:
 
   * `["EVENT", <event JSON as defined above>]`, used to publish events.
-  * `["REQ", <subscription_id>, <filters JSON>, ...]`, used to request events and subscribe to new updates.
+  * `["REQ", <subscription_id>, <filters1>, <filters2>, ...]`, used to request events and subscribe to new updates.
   * `["CLOSE", <subscription_id>]`, used to stop previous subscriptions.
 
-`<subscription_id>` is an arbitrary, non-empty string of max length 64 chars, that should be used to represent a subscription. Relays should manage `<subscription_id>`s independently for each WebSocket connection; even if `<subscription_id>`s are the same string, they should be treated as different subscriptions for different connections.
+`<subscription_id>` is an arbitrary, non-empty string of max length 64 chars. It represents a subscription per connection. Relays MUST manage `<subscription_id>`s independently for each WebSocket connection. `<subscription_id>`s are not guarantueed to be globally unique.
 
-`<filters>` is a JSON object that determines what events will be sent in that subscription, it can have the following attributes:
+`<filtersX>` is a JSON object that determines what events will be sent in that subscription, it can have the following attributes:
 
 ```json
 {