Q:

How to implement a Web UI feature to insert default sentences in an textarea

We are talking about implementing a system that easily generates sales reports for our sales employees. We want to create a web application with one or maybe more text area's to gather the input data from the employee.
There are a few sentences that will return time and time again. Something like: "customer xyz decided to buy the products advised by consultant abc"
What options do I have to implement a feature like that. What I already thought of:

Click RMB in text area to pop the sentences or categories of sentences which can be selected. Feels a bit outdated to me.
Shortcuts, like an IDE. When I type psvm[tab] I get "public static void main...". Probably to technical for most users.
Present a box with sentences next to the text area from which you can drag and drop the sentences. This will take up a lot of real estate.
When the system recognizes the start of a sentence that is in the default sentences it pops the sentence and can be clicked (something like the tag functionality here on SE). This will give a lot of false true's which might be annoying for the user.

I understand that there is not a single right answer to this question. Please post answers preferably with an example (of some other site)

A:

When the system recognizes the start of a sentence that is in the default sentences it pops the sentence and can be clicked (something like the tag functionality here on SE). This will give a lot of false true's which might be annoying for the user.

I would go with this one. It's done in Microsoft Excel (which is fairly ubiquitous). The only time this might get annoying is if the user had to take extraordinary measures to change it. (If they kept typing something else, the default would disappear)
If you are unsure about it, test it with a few people who will be using the system. It's the only way to be sure.

