I'm using a BSD-2 Licence code in my project and with author permission, I modify the code. Now, I am using this code in my project. I know, I should mention Author's name and copyright information. Should, I mention What I modify in this code??
3 Answers
The 2-clause BSD license requires that you advertise the names of the original authors (my emphasis):
Copyright (c) [YEAR], [OWNER].
All rights reserved.
(...)
Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
The same goes for the binary form:
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
A binary release, obviously, doesn't require that you identify clearly what parts of the source code the original copyright applies to.
A source code release however would have you include the copyright in each original file, and put your own in each of your files. In case a file has been patched, and thus contains code from both the original author and yourself, you would have to stack the copyrights at the top of the file. At least, this is what seems to be the general practice to me.
Should, I mention What I modify in this code[? ...]
You must mention which code is by that person. So if you modify the code, you can do that by writing that you changed it and what you changed.
So yes, you should mention what you modified otherwise it's not clear which code has been made by whom. And the BSD requires you to make visible - at least for the code under it - which code it relates to.
This is one of the requirements the license BSD has.
You note in your answer that you got the authors permission to modify the code. This means that you now have a license, separate from the BSD license, to create a derived work. I would go back to the original author and ask if and how the author wants to be credited.