Powershell Help system usage

Question

I am learning powershell, so first i am learning how to use the help system of powershell. Below is the help for command "Get-EventLog",

1. what do we mean by : Position? named

2. Also is there any links to get more on how to use the help system provided by powershell?

   Synopsis Gets the events in an event log, or a list of the event logs, on the local or remote computers.

      Syntax   Get-EventLog [-LogName] <String> [[-InstanceId] <Int64[]>] [-After <DateTime>] [-AsBaseObject <SwitchParameter>] [-Before <DateTime>] [-ComputerName <String[]>] [-EntryType <String[]>] [-Index <Int32[]>] [-Message <String>] [-Newest <Int32>] [-Source <String[]>] [-UserName <String[]>] [<CommonParameters>]
   
   Get-EventLog [-AsString <SwitchParameter>] [-ComputerName <String[]>] [-List <SwitchParameter>] [<CommonParameters>]
   
    Parameters
            -After <DateTime>
                   Gets only the events that occur after the specified date and time. Enter a DateTime object, such as the one returned by the Get-Date cmdlet.
               Required?                    false
               Position?                    named
               Default value                
               Accept pipeline input?       false
               Accept wildcard characters?  false
   
           -InstanceId <Int64[]>
               Gets only events with the specified instance IDs.
               Required?                    false
               Position?                    2
               Default value                
               Accept pipeline input?       false
   
               Accept wildcard characters?  false
   
           -LogName <String>
               Specifies the event log.  Enter the log name (the value of the Log property; not the LogDisplayName) of one event log. Wildcard characters are not permitted. This parameter is required.
               Required?                    true
               Position?                    1
               Default value                
               Accept pipeline input?       false
               Accept wildcard characters?  false
   

Answer 1

For #1, you need to understand how positional parameters are used in PowerShell. You can refer to the following scripting guys article on that.

http://blogs.technet.com/b/heyscriptingguy/archive/2012/04/22/the-problem-with-powershell-positional-parameters.aspx

For #2, in PowerShell v3, there is update-able help. By default, on PowerShell 3.0 systems, there is no help installed. Everything is online. You can download the help content using Update-Help and Save-Help cmdlets.

Also, Get-Help <cmdletname> -Online shows the online (most up-to-date) content for any cmdlet.

You can use the about topics in PowerShell to learn the concepts. These about topics can be accessed using help about*. You will see a huge list of topics which can be accessed using help or Get-Help. For example,

help about_Parameters

Once again, if you are using PowerShell 3.0, you need to update the help first to be able to see any help content.

Answer 2

You can first have a look to about_Command_Syntax

get_help about_Command_Syntax

Then have a look at a few other abouts, if you want to add your own help to your Cmd-Lets have a look here.