This is where the work history and various other sections of the resume come in. Explain some of the most significant projects you've worked on and describe th

This is where the work history and various other sections of the resume come in. Explain some of the most significant projects you've worked on and describe the nature of your contributions. If you describe 10 years of experience in web development environments using PHP, when you put C in your skills section it will be clear that C is not one of your core skills. You're probably trying to make the point that you can read and understand C if you have to, and if that's important to the employer they should follow up.