Start a "conventions" section to span all the specs

It's short for now, but we will extract more and more things from
the rest of the specifications as we continue editing.

2 files changed, 3 insertions, 25 deletions

diff --git a/spec/tor-spec/opening-streams.md b/spec/tor-spec/opening-streams.md
index d59e26b..757f776 100644
--- a/spec/tor-spec/opening-streams.md
+++ b/spec/tor-spec/opening-streams.md
@@ -26,8 +26,9 @@ fingerprinting.  Implementations MUST accept strings in any case.
 
 The FLAGS value has one or more of the following bits set, where
 "bit 1" is the LSB of the 32-bit value, and "bit 32" is the MSB.
-(Remember that all values in Tor are big-endian (see
-["Preliminaries » Encoding integers"](./preliminaries.md#encoding)), so
+(Remember that
+[all integers in Tor are big-endian](../intro/conventions.md),
+so
 the MSB of a 4-byte value is the MSB of the first byte, and the LSB
 of a 4-byte value is the LSB of its last byte.)
 
diff --git a/spec/tor-spec/preliminaries.md b/spec/tor-spec/preliminaries.md
index 8cc92b7..60359af 100644
--- a/spec/tor-spec/preliminaries.md
+++ b/spec/tor-spec/preliminaries.md
@@ -2,13 +2,6 @@
 
 # Preliminaries
 
-```text
-      The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
-      NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED",  "MAY", and
-      "OPTIONAL" in this document are to be interpreted as described in
-      RFC 2119.
-```
-
 <a id="tor-spec.txt-0.1"></a>
 
 ## Notation and encoding{#notation-and-encoding}
@@ -23,26 +16,10 @@
    a|b -- concatenation of 'a' and 'b'.
 ```
 
-\[A0 B1 C2\] -- a three-byte sequence, containing the bytes with
-hexadecimal values A0, B1, and C2, in that order.
-
 H(m) -- a cryptographic hash of m.
 
-We use "byte" and "octet" interchangeably.  Possibly we shouldn't.
-
 Some specs mention "base32".  This means RFC4648, without "=" padding.
 
-<a id="tor-spec.txt-0.1.1"></a>
-
-### Encoding integers{#encoding}
-
-Unless we explicitly say otherwise below, all numeric values in the
-Tor protocol are encoded in network (big-endian) order.  So a "32-bit
-integer" means a big-endian 32-bit integer; a "2-byte" integer means
-a big-endian 16-bit integer, and so forth.
-
-<a id="tor-spec.txt-0.2"></a>
-
 ## Security parameters
 
 Tor uses a stream cipher, a public-key cipher, the Diffie-Hellman