Vim Tip: Partial Search & Replace

So, you have a paragraph, or any kind of text, and need to replace a substring without altering other paragraphs. You could write :set number and then :A,Bs/what to search/what to replace/g, being A and B the start and end of the paragraph, or you could just use visual mode.

Enter line selection mode (Shift + V) and then select a block of text. Without moving the cursor any further type :s/SEARCH/REPLACE and the search string in the selected block will be replaced without altering any other part of the document.