Home > Articles > Programming > Windows Programming

Robert C. Martin's Clean Code Tip of the Week #3: Avoid Inappropriate Information

We join "The Craftsman," Robert C. Martin's series on an interstellar spacecraft where programmers hone their coding skills. In this third tip of the series, the programmers discuss how to avoid inappropriate information.
You can review additional articles from Robert C. Martin's series, "The Craftsman," on the ObjectMentor website.
Like this article? We recommend
December 31, 1944, 23:55:00

Wallace and Truman celebrated the New Year with the White House staff.  Though the music was good, and the party was lively, both men kept nervously looking at their watches.  If the other party-goers thought the men were steeling themselves for the inevitable speeches they’d soon be making, they were mistaken.

As the clock struck midnight, a new sun blossomed in the Nevada desert.  Riding that fervent impulse was a vessel the size of the Lincoln Memorial.  A second later, and a 100’ in the air, another sun blared forth, followed by another, and then another. 

The shock absorbers between the cabin and the pusher plate damped the 1-kiloton blasts. The twenty crewmen aboard felt the G forces rise and fall as though they were swinging high on a playground swing set.

They were on their way to see Clyde.

Thursday, 7 Mar 2002, 14:00

The "Brown-Bag" was boring today.  One of the virtual attendees gave a talk about some big framework.  I didn’t get the name, but I think it rhymed with "sore".

I left before it was over.  Jasmine followed me out and faked stifling a yawn.  We both smirked.  Then she asked me if I’d mind pairing a bit with Adelaide.  So after lunch I put the finishing touches on a module, made sure all the tests passed, pushed the module to github, fired off a Hudson build, and then sauntered over to where Adelaide was working. 

"Hi Alphonse, thanks for stopping by." she murmured, never taking her eyes off the screen.

"Sure." I said, as I looked at her screen.  She had a new module up, and it looked like she was just typing it from scratch.  The only thing on the screen was:



 * Farvle -- a class that performs 'Farvle' operations

 *           on 'Arvadents' and other slithy toves.

 * @Date: 7 Mar, 2002

 * @Ship: Dyson

 * @Guild: Mr. C

 * @Author: Adelade

 * Version History:

 * 20020307 adl -- initial version.


public class Farvle {



"Adelaide, why did you type all of that?"

She looked a question at me, but did not answer.

"Did Jasmine tell you to do that?"

"N-no." she stammered, "This is how they taught us to start a module in CS."

"You’ve been working with Jasmine for a few days now, have you ever seen anything like this at the front of the modules that you and she have worked on together?"

"N-no, I had wondered about that." She mewled.  "It seemed to me that those modules weren’t very well documented."

"Are you familiar with Mr. C’s Clean Code rules?"

She hung her head and mumbled: "I haven’t had time to read through them all yet."

"OK." I said. "The first rule of comments (C1) is: ‘Avoid Inappropriate Information’".

She looked at me strangely for a split second, and then stared at her lap.  I thought she wasn’t going to respond, but a moment later she gritted her teeth and forcefully said: "I don’t see anything inappropriate about that information."

I realized I needed to tread gently.  After all, I was only a few days more senior than she.  So I carefully held out my hands for the keyboard and said: "May I"?

She looked at me from the corner of her eye, and passed the keyboard my way. 

"Thank you.  Now have you created a git repository for this yet?"

"No." she said.  "Not yet."

"Then please allow me." And so I saved the module and typed the commands that would create a git repository and commit her module into it.


$ git init

$ git add src/Farvle.java

$ git commit –m “initial commit”


I handed the keyboard back to her and said:  “OK, now type git log”.

She did as I asked, and up on the screen came the following message:


$ git log

commit a4c3868b8386ce5f7eeae2a449f8ef8c89081af5

Author: adelade <adelade@mrc.dyson.gld>

Date:   Thu Mar 7 14:06:06 2002


    initial commit


"All that information that you had put into your source file is in the git log. There’s nothing inappropriate about the information itself; but the source file is the wrong place for it." 

She was staring at her lap again, and I could see that she was building up to a protest.  So I quickly brought the Clean Code rules up on the screen. 

C1: Inappropriate Information

It is inappropriate for a comment to hold information better held in a different kind of system such as your source code control system, your issue tracking system, or any other record-keeping system.  Change histories, for example, just clutter up source files with volumes of historical and uninteresting text.  In general, meta-data such as authors, last-modified-date, SPR number, and so on should not appear in comments.  Comments should be reserved for technical notes about the code and design.

She looked at the screen for several minutes, and then sat back in her seat and looked over at me.

"OK, I get it." She said.  "But then why did my CS teachers tell me to put all that stuff in my source files?"

I sighed, the way I’d seen Jerry sigh when I asked him questions like that.  Then I gave her the answer that he gave me:  "They teach you a lot of goofy things in school, Adelade."

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020