In PDF viewing software is basically a character can not be input to the file.
However, the field be provided to enable the viewer's input, known as "form fields" when creating the PDF file, only in that field will be able to print Type the characters in the browsing software.
Say that save in the state you entered Unfortunately, the change of the PDF file can not be other words, can be printed in the state you enter a character, so you finish clean and efficient than handwritten to print the base paper It is very convenient.
If you want to publish it to a PDF file an application for something, it is recommended that you set the form fields to fill column.
Some, such as PDF creation software "Adobe Acrobat Standard", you can set a form field to an existing file.
There are also specialized products, such as "gentle character input to PDF", the ability to enter text.