diff --git a/protocols/osi1-2/eth-frame.yml b/protocols/osi1-2/eth-frame.yml
index 893b40a..c69c3f0 100644
--- a/protocols/osi1-2/eth-frame.yml
+++ b/protocols/osi1-2/eth-frame.yml
@@ -1,7 +1,7 @@
 #Ethernet
 ---
-protocol: &eth
-  name: eth
+protocol: &ethframe
+  name: eth-frame
   osilayer: 2
   fields:
     - 
diff --git a/protocols/osi1-2/eth-packet.yml b/protocols/osi1-2/eth-packet.yml
new file mode 100644
index 0000000..026ee8e
--- /dev/null
+++ b/protocols/osi1-2/eth-packet.yml
@@ -0,0 +1,15 @@
+---
+protocol: &ethpacket
+  name: eth-packet
+  osilayer: 1
+  fields:
+    -
+      field: preamble
+      length: 7
+    -
+      field: Start of frame delimiter
+      length: 1
+    - field: eth-frame
+      length: 0
+      data: true
+      reference: eth-frame
\ No newline at end of file
diff --git a/protocols/osi3/ip.yml b/protocols/osi3/ip.yml
new file mode 100644
index 0000000..40734c8
--- /dev/null
+++ b/protocols/osi3/ip.yml
@@ -0,0 +1,70 @@
+---
+protocol:
+  name: internet protocol version 4
+  shortname: ipv4
+  osilayer: 3
+  fields:
+    - field: version
+      desc: Version
+      bitfield: yes
+      length: 4
+    - field: IHL
+      desc: internet header length (IHL)
+      bitfield: yes
+      length: 4
+    - field: DSCP
+      desc: differential services code point (DSCP)
+      bitfield: yes
+      length: 6
+    - field: ECN
+      desc: explicit congestion notification (ECN)
+      bitfield: yes
+      length: 2
+    - field: packetlength
+      desc: total length (incl. header)
+      length: 2
+    - field: id
+      desc: identification
+      length: 2
+    - field: flags
+      desc: fragment flags
+      bitfield: yes
+      length: 3
+      subfields:
+        - field: reserved
+          desc: reserved
+          bitfield: yes
+          length: 1
+        - field: df
+          desc: don't fragment (DF)
+          bitfield: yes
+          length: 1
+        - field: mf
+          desc: more fragments (MF)
+          bitfield: yes
+          length: 1
+    - field: fragmentoffset
+      desc: fragment offset
+      bitfield: yes
+      length: 13
+    - field: TTL
+      desc: time to live (TTL)
+      length: 1
+    - field: protocol
+      desc: protocol id
+      length: 1
+    - field: headerchecksum
+      desc: header checksum
+      length: 2
+    - field: source
+      desc: source ip address
+      length: 4
+    - field: destination
+      desc: destination ip address
+      length: 4
+    - field: options
+      desc: options (if IHL > 5)
+      length: 4
+      optional: yes
+    - field: data
+      data: true
\ No newline at end of file
diff --git a/structure-schema.yml b/structure-schema.yml
index 7bdcac7..4c7d470 100644
--- a/structure-schema.yml
+++ b/structure-schema.yml
@@ -7,26 +7,31 @@ mapping:
       "name": 
         type: str
         required: yes
+      "shortname": 
+        type: str
       "fields": 
         type: seq
         required: yes
         sequence: &fieldsseq
           - type: map
             mapping: 
-              "field": 
+              "field": #field name (best if only one word, for easier referencing)
                 type: str
                 required: yes
+              "desc": #short description
+                type: str
               "length": #length in bytes, except bitfield is set to true!
                 type: int
-                required: yes
               "bitfield": #if this is true length is in BITS!
                 type: bool
               "optional":
                 type: bool
               "repeatable":
                 type: bool
-              "data": #data placeholder for next layer (length should be 0!)
+              "data": #data placeholder for next layer
                 type: bool
+              "reference": #reference another protocol directly (e.g. ethpacket->ethframe) 
+                type: str
               "subfields": 
                 type: seq
                 sequence: *fieldsseq