What's the best way to describe your level of skill in particular technologies (languages, platforms, OS, ...) when polishing your CV ?
Assume we are talking about the short CV of the kind where you don't spell out every project and system you have worked on in the past, but still want the reader to get a general appreciation of how well you master each topic.
Can you suggest a set of labels which is unambiguous but sufficiently general to be understood across the industry?
Number of years of experience is usually what HR people look for since it is more verifiable and ostensibly objective than words like "expert" et. al.
You could use a scale system, e.g. 1-5 with 1 being the least and 5 being the most. Be quantitative not qualitative as that can bring in various definitions that aren't likely to be what you'd prefer.
Labels are so ambiguous as to be meaningless. Instead, describe working projects you have actually done in each language. E.g. "Wrote 30 T/SQL stored procedures for SQL Server 2005 for updating an ORM, and 10 triggers for integrity validation". "Wrote back-end LINQ to SQL ORM in C# for an ASP.Net 3.5 web service".
As a hiring manager, I like it when people state how many years they used a language and when they last used it. Also, when describing projects you worked on, be sure to list what languages you used on each. It's frustrating to see someone with C++ (or any language) on their resume but not listed next to any projects.
In past years, I have added qualitative terms to my resume but only in a structured way. So, for example, I've used things like "Expertise in C#, SQL and Delphi" and then "Familiar with Lisp, PHP,..." etc. The idea isn't necessarily to rank yourself against others - the years of experience and the types of projects worked on will do that - it is to show where you are deepest in a relative sense among all of the technologies that you have learned.
The other benefit, of course, is that you are showing a sense of proportion and perspective about your own talents. If you said you were "expert" in more than three technologies, I'd be pretty skeptical. If you indicated expertise in 2-3 and familiarity with many more, it would raise much less of a red flag.