Proper usage of the punctuation / (Slash)

I never realised that I was using / wrongly until I googled it. I'm sure you already know this but if you didn't, hope you enjoy the read.

The slash (/), also called the oblique, the virgule, the stroke, the solidus or the shilling mark, are generally used based on these rules:

1. In fractions
   (To separate a numerator from a denominator in a numerical fraction. Do not place a space before or after the slash in a fraction.)
   
   • 1/2 (one half)
   • 2/3 (two thirds)
   • 9/10 (nine tenths)
   
   
2. In dates
   (To separate the month, day, and year, in an informal representation of a date. Do not place a space before or after the slash in a date.)
   
   • On credit card: Expires end 10/15 (October 2015)
   • He was born on 30/11/2007. (30th November 2007)
   • It was invented on 11/30/2007. (November 30th, 2007)
   
   
3. With abbreviations
   (Used in writing certain abbreviations. Do not place a space before or after the slash in an abbreviation.)
   
   • c/o (care of)
   • w/ (with)
   • w/o (without)
     
     
4. Separate alternatives
   (To indicate "or", "and" or "and/or". Do not use a slash to join coequal nouns; use a hyphen instead.)
   
   • Dear Sir/Madam (Sir or Madam)
   • Please press your browser's Refresh/Reload button. (Refresh or Reload)
   • The speech will be given by President/Senator Clinton. (President Clinton or Senator Clinton)
   • Mary will eat cake and/or fruit. (Mary will eat cake, or Mary will eat fruit, or Mary will eat cake and fruit.)
     
     
5. Indicate line breaks
   (To indicate line breaks in quotations of less than four lines of poetry. Place a space before and after a slash that indicates a line break in a poem.)
   
   • Shel Silverstein ends his poem "Where the Sidewalk Ends" with a walk: "Yes we'll walk with a walk that is measured and slow, / And we'll go where the chalk-white arrows go, / For the children, they mark, and the children, they know / The place where the sidewalk ends."
   • "I heard a Fly buzz – when I died – / The Stillness in the Room," begins "I heard a Fly buzz – when I died" by Emily Dickinson.
     
     
6. In scientific writing
   (To represent the word per in units. Do not place a space before or after the slash.)
   
   • The speed limit is 100 km/h. (kilometres per hour)
   • He can type at 75 w/m. (words per minute)
   • The eggs cost $3/dozen. ($3 per dozen)
   • They charge £1.50/litre for petrol. (£1.50 per litre)
     
     
7. With file names and Internet addresses
   (Used to separate parts of a website address (url) on the Internet, and to separate folders on some computer systems. Do not place a space before or after the slash in a file name or Internet address.)
   
   • http://www.englishclub.com/writing/punctuation-slash.htm
   • file:///Users/mac/tara/photos/image.jpg