I'm parsing x509, versions 1 and 3. I found the version field in the v3 cert, but I have two v1 certs (one from my organization, one I generated via OpenSSL) and in both of these the first non-sequence field is the serial number integer:

```
    > openssl asn1parse -in ca.der -inform DER
    0:d=0  hl=4 l= 645 cons: SEQUENCE          
    4:d=1  hl=4 l= 494 cons: SEQUENCE          
    8:d=2  hl=2 l=   9 prim: INTEGER           :B7D50AE5F7DB09FD
    .
    .
    .

```

The reason I'm confused is that the wording in [RFC 1422](https://www.ietf.org/rfc/rfc1422) seems to quite clearly suggest that the version is an actual field and that it is the first field, before the serial number:

```
  3.3  Certificate Definition

   Certificates are central to the key management architecture for X.509
   and PEM.  This section provides an overview of the syntax and a
   description of the semantics of certificates.  Appendix A includes
   the ASN.1 syntax for certificates.   A certificate includes the
   following contents:

       1.  version

       2.  serial number

       3.  signature (algorithm ID and parameters)

       4.  issuer name

       5.  validity period

       6.  subject name

       7.  subject public key (and associated algorithm ID)

   3.3.1  Version Number

   The version number field is intended to facilitate orderly changes in
   certificate formats over time.  The initial version number for
   certificates used in PEM is the X.509 default which has a value of
   zero (0), indicating the 1988 version.  PEM implementations are
   encouraged to accept later versions as they are endorsed by
   CCITT/ISO.
   .
   .
   .

```

I'm looking at RFC 1422 because [wikipedia](https://en.wikipedia.org/wiki/X.509#Structure_of_a_certificate) says:

> 
> "The structure of version 1 is given in RFC 1422."
> 
> 
> 

My expectation is to find an integer field of length 1 with value `0x00` before the serial number in a v1 cert.

Is version 0x00 (v1) just implicit? That is, will there only be a version field if version > 0x00? What does this mean for the version field description in RFC?