T-carriers are a type of high-capacity digital line generally used to carry voice, data, and other content over long distances. The higher the figure, the larger the capacity of the line. T1 lines are used by many large organizations to connect to the Internet.
When a document is long (more than 10 paragraphs), you should provide a table of contents (TOC). Generally it should be placed between the summary and the main body of text, and should be generated from subheads within the documents. In long documents, you should use subheads approximately every five paragraphs. The TOC should be linked to its corresponding subhead within the document.