As the GIS Manager where I work, part of my job includes managing our License Server and ensuring that users who are authorized a GIS license can get one, and those who are not can't -- even if the latter somehow knows the name of the license server.
This is where the Options File comes into play for the ArcGIS License Server Administrator. Using the Options file, you can do all kinds of very cool things such as grant users and/or groupings of users (or machines and/or groupings of machines or even IP addresses and/or groupings of IP addresses) access to certain licenses and extensions, restrict the cumulative number of licenses groups can use concurrently, outright restrict certain licenses and all sorts of other whiz-bang crazy stuff all you control freaks out there will really love.
That's where my favorite Text Editor, Notepad++ comes in. It's a basically an enhanced text editor with all kinds of helper tools and plugins available. In addition, you can create your own Syntax Highlighter for custom code. With that, I decided to create a Syntax Highlighter for the ArcGIS Options file so that I could quickly make sense of everything I had written and ensure my syntax was consistent and correct.
The syntax highlighter is a simple UDL file that you can import into Notepad++.
Language ==> Define your language ===> Import
Once you've done that, you'll see the item 'AGS License Opt' in the Language menu of Notepad++. Selecting that option will highlight keywords in the options file when you type then, based on what that keyword does.
The breakdown of the syntax highlighting is as follows:
Comments are highlighted in green, formatted as Bold and denoted by a hashtag (#)
# This is a comment
Internal Feature Names
Internal Feature Names are organized into two classifications;
Internal Feature Names which refer to one of the three licensing levels of the core ArcGIS for Desktop product are highlighted in royal blue and denoted by one of the following Internal Feature Names:
Internal Feature Names which refer to an ArcGIS for Desktop Extension product are highlighted in light blue and denoted by one of the following internal feature names. I couldn't find a comprehensive listing of Internal Feature Names so if I missed something, please let me know in the comments.
Option keywords used to manage licenses by allocating or restricting them are highlighted in a orange and denoted by one of the following keywords:
Option keywords used to group together Type-options are highlighted in pink and denoted by one of the following keywords:
Option keywords used to specify what Type of parameter the Option is based on (referred to as a "Type" in the ArcGIS Options file documentation) are highlighted in red and denoted by one of the following keywords:
Option keywords which affect behavior of the License Server but do not affect the actual management of the licenses are highlighted in grey and denoted by one of the following keywords:
The result of all of this is a much more intuitive options file that makes defining and editing the License Server Options file much easier. It also reduces mistakes since you can see how your syntax is structured and validate that you are using the correct keywords and internal feature names with a simple glance, ie. if your keyword isn't highlighted, it's probably not valid.
If you don't like the default highlighting settings once you've imported the UDL, you can change them very easily in Notepad++ by clicking the "Define your language..." option in the Language menu of Notepad++, selecting "AGS License Opt" from the User Language combobox and tinkering with the settings behind each of the Styler buttons for each keyword group.