diff --git a/API-Component.md b/API-Component.md
index 36fc58b..3065d7d 100644
--- a/API-Component.md
+++ b/API-Component.md
@@ -8,8 +8,12 @@ The component API is used to access and interact with components available to a
   Gets the proxy for the primary component of the specified type. Throws an error if there is no primary component of the specified type.
 - `component.setPrimary(componentType: string, address: string)`  
   Sets a new primary component for the specified component type. The address may be abbreviated, but must be valid if it is not `nil`. Triggers the `component_unavailable` and `component_available` signals if set to `nil` or a new value, respectively.
-- `component.list()`  
-  Returns an iterator which returns `address,type`.
+- `component.list([filter: string]): function`  
+  Returns an iterator which returns pairs of `address, type` for each component connected to the computer. It optionally takes a filter - if specified this will only return those components for which the filter is a substring of the component type. For example:
+```lua
+-- prints `redstone` for each attached redstone card.
+for _, name in component.list("red") do print(name) end
+```
 
 Note that the component API has a metatable that allows the following syntax:
 ```lua