Update marketplace.md

codex/marketplace.md

@@ -31,12 +31,15 @@ simplify incentive mechanism.
 | Regular Nodes | The Main Codex client that interacts with other nodes to locate and retrieve data. Can also be considered a ephemeral node(light client) |
 | Slots | An agreement with storage nodes and regular nodes to store data |
 
-The Codex network provides a marketplace where regular nodes can create a storage request on the blockchain to store data.
-A Codex node can request storage of arbitrary data by creating open slots on the blockchain. 
-The requester SHOULD include the following:
 
 ### Storage Request
 
+A Codex regular node can request storage of arbitrary data by creating open slots on the blockchain. 
+When a request is made by a regular node,
+a storage contract is opened on the marketplace via the blockchain, and 
+storage nodes can then decide to store the data.
+The requester SHOULD initiate the contract with the following:
+
 ```protobuf
 
 requestStorage {
@@ -66,10 +69,24 @@ requestStorage {
 
 ```
 
-- `cid` MUST be a sha2-256 hash (length 32 bytes, base58) of the data being stored
-- 
+`cid` 
+- MUST be a sha2-256 hash (length 32 bytes, base58) of the data being stored
+- MUST be generated by the requester, or regular node
+`reward`
+- SHOULD be token known to the network.
+- it MUST be paid directly to storage nodes that agree to contract
+
+`collateral`
+All storage nodes MUST provide token collateral before being able to fullfill a storage contract.
+The collateral will taken to punish the storage node when that node does not follow the contract.
+The following conditions MUST be fullfilled in a Codex storage contract
+- failing to provide proofs periodically, the RECOMMENDED method for proofs is [Proof-of-Data-Possession](https://hackmd.io/2uRBltuIT7yX0CyczJevYg?view).
+- a portion of `collateral` MUST be offered as rewards vaildator nodes,
+and a portion SHOULD be offered as reward to storage nodes that repair [slots](##slots)
+
+`proofProbability`
+
 
-The contract will be open to any storage node willing to accept to store the data.
 
 ### Slots