A '<<document call>>' is a special setup that results in an insertion of Boilerplate text at the point of the call. To setup a document call, simply type the name of a document in your Boilerplate text collection between a pair of angle brackets (lesser than and greater than signs, for you math majors).
When the below text is processed, Pathagoras On Cloud looks to the files in the Boilerplate folder and sub-folders to find the 'ltrhead' and 'sigline' documents. They are then copied and inserted in place of the called <<documents>>.
Copy and paste the below text into an editing and press Alt-P ('p'rocess) to see how elegant and fast document assembly in this fashion can be. (These terms actually exist in your Boilerplate folder, having been copied there during the initial setup of your account. You can freely edit them to fit your office's needs.)
[Date of Letter]
Thank you for your purchase of [quantity] widgets.
They will be shipped via [UPS/Parcel Post/FedEx] within 10 days.
(Note: the 'painting' of the sample text above is for illustration and emphasis only. Colors are not required.)