Update FLEDGE.md

FLEDGE.md

@@ -24,6 +24,7 @@ We plan to hold regular meetings under the auspices of the WICG to go through th
     - [3.2 On-Device Bidding](#32-on-device-bidding)
     - [3.3 Metadata with the Ad Bid](#33-metadata-with-the-ad-bid)
     - [3.4 Ads Composed of Multiple Pieces](#34-ads-composed-of-multiple-pieces)
+    - [3.5 Prioritizing Interest Groups](#35-prioritizing-interest-groups)
   - [4. Browsers Render the Winning Ad](#4-browsers-render-the-winning-ad)
   - [5. Event-Level Reporting (for now)](#5-event-level-reporting-for-now)
     - [5.1 Seller Reporting on Render](#51-seller-reporting-on-render)
@@ -88,6 +89,17 @@ const myGroup = {
   'owner': 'https://www.example-dsp.com',
   'name': 'womens-running-shoes',
   'priority': 0.0,
+  'priorityVector': {
+    'signal1': 2,
+    'signal2': -3.5,
+    ...
+  }
+  'prioritySignalsOverrides': {
+    'signal1': 4.5,
+    'signal2': 0,
+    ...
+  }
+  `enableBiddingSignalsPrioritization` : [true | false],
   'biddingLogicUrl': ...,
   'biddingWasmHelperUrl': ...,
   'dailyUpdateUrl': ...,
@@ -114,6 +126,10 @@ The browser will remain in an interest group for only a limited amount of time.
 
 The `priority` is used to select which interest groups participate in an auction when the number of interest groups are limited by the `perBuyerGroupLimits` attribute of the auction config. If not specified, a `priority` of `0.0` is assigned. There is no special meaning to these values. These values are only used to select interest groups to participate in an auction such that if there is an interest group participating in the auction with priority `x`, all interest groups with the same owner having a priority `y` where `y > x` should also participate (i.e. `generateBid` will be called). In the case where some but not all interest groups with equal priority can participate in an auction due to `perBuyerGroupLimits`, the participating interest groups will be uniformly randomly chosen from the set of interest groups with that priority.
 
+`priorityVector`, `prioritySignalsOverrides`, and `enableBiddingSignalsPrioritization`, are optional values use to dymnically calculate a priority used in place of `priority`. `priorityVector` and `prioritySignalsOverrides` are mappings of strings to Javscript numbers, while enableBiddingSignalsPrioritization is a bool that defaults to false. See [Prioritizing Interest Groups](#35-prioritizing-interest-groups) for a description of these fields.
+
+`prioritySignalsOverrides` is an optional mapping of string keys to Javascript numbers that, if present, will override the corresponding values in a `prioritySignals` vector when using a `priorityVector` to calculate an interest group's priority. See [Prioritizing Interest Groups](#35-prioritizing-interest-groups) for more information.
+
 The `userBiddingSignals` is for storage of additional metadata that the owner can use during on-device bidding, and the `trustedBiddingSignals` attributes provide another mechanism for making real-time data available for use at bidding time.
 
 The `biddingWasmHelperUrl` field is optional, and lets the bidder provide computationally-expensive subroutines in WebAssembly, rather than JavaScript, to be driven from the JavaScript function provided by `biddingLogicUrl`. If provided, it must point to a WebAssembly binary, delivered with an `application/wasm` mimetype. The corresponding `WebAssembly.Module` will be made available by the browser to the `generateBid` function.
@@ -183,6 +199,13 @@ const myAuctionConfig = {
                         'https://www.another-buyer.com': 1000,
                         '*': 15,
                         ...},
+  'perBuyerPrioritySignals': {'https://www.example-dsp.com': {
+                                'signal1': 2.5,
+                                'signal2': 2.5,
+                                ...},
+                              'https://www.another-buyer.com': {...},
+                              '*': {...},
+                              ...},
   'componentAuctions': [
     {'seller': 'https://www.some-other-ssp.com',
       'decisionLogicUrl': ...,
@@ -204,6 +227,8 @@ Optionally, `sellerTimeout` can be specified to restrict the runtime (in millise
 
 Optionally, `perBuyerGroupLimits` can be specified to limit the number of of interest groups from a particular buyer that participate in the auction. A key of `'*'` in `perBuyerGroupLimits` is used to set a limit for unspecified buyers. For each buyer, interest groups will be selected to participate in the auction in order of decreasing `priority` (larger priorities are selected first) up to the specfied limit. The selection of interest groups occurs independently for each buyer, so the priorities do not need to be comparable between buyers and could have a buyer-specific meaning. The value of the limits provided should be able to be represented by a 16 bit unsigned integer.
 
+Optionally, `perBuyerPrioritySignals` is an object mapping string keys to Javascript numbers that can be used to dynamically compute interest group priorities at the start of the auction, before perBuyerGroupLimits are applied. See [Prioritizing Interest Groups](#35-prioritizing-interest-groups) for more information.
+
 All fields that accept arbitrary metadata objects (`auctionSignals`, `sellerSignals`, and keys of `perBuyerSignals`) must be JSON-serializable.
 
 A `Permissions-Policy` directive named "run-ad-auction" controls access to the `navigator.runAdAuction()` API.