Course Catalog / BMU 030 / Lesson 4 of 5
BMU 030
Lesson 4: Kinds of mail: must do, can do, just so you know
Quick review
1. What do you look for when you skim?
See the answer
Headings, dates, amounts, and words like must.
2. Where is the main point most often?
See the answer
Near the start.
Why this matters
Some letters need you to act. Some give you a choice. Some just tell you something. If you can tell which is which, you know what to do first.
In this lesson you will sort mail into must do, can do, and just so you know.
Start with what you already do
You already know a bill needs paying and an ad does not.
Common belief: Every official letter means I am in trouble.
What is actually true: Many letters are only to keep you informed. The IRS says you do not need to reply unless the letter asks you to.
In this lesson you will
- Tell must do, can do, and just so you know lines apart
- Name common kinds of mail
- Put must do mail first
Key words
- must
- You have to do it.
- may
- You can choose to do it.
- for your information
- Just so you know. No action needed.
Three kinds of lines
The Federal Plain Language Guidelines tell government writers to use must for a requirement and may for a choice. They use should for advice.
| Kind | Words to look for | Example |
|---|---|---|
| Must do | must, required, you need to, due by | You must send a copy of your ID. |
| Can do | may, you can, optional, if you want | You may call us with questions. |
| Just so you know | for your records, no action needed, this is to inform you | This is for your records. |
Common kinds of mail
| Kind of mail | What to look for |
|---|---|
| Bill | Amount due and a due date. |
| Notice | Something changed or something is needed, often with a date. |
| Lease or contract page | Rules you agreed to, like rent dates and fees. |
| School letter | Events, forms to sign, and dates. |
Put must do mail first
Make a small must do pile with the deadline on top. The IRS says, even if you cannot pay the full amount you owe, pay by the due date. That can lower interest and penalty charges. If you disagree with a letter, follow its steps to dispute it, and reply by the due date.
Text version of this figure
Must do, can do, just so you know. Sort first, then act.
- Must do: must, required, due by. Act by the date.
- Step 1, Can do: may, optional. Your choice.
- Step 2, Just so you know: for your records. Keep it.
- Must do pile first: Soonest deadline on top.
- Keep official mail: File it where you can find it.
Source: Federal Plain Language Guidelines; IRS (Oct 29, 2026).
Worked example: Jay sorts a week of mail
Jay has five letters.
- A power bill, due on the 12th: must do.
- A school letter that says you may join the parent meeting: can do.
- A bank letter that says this is for your records: just so you know.
- A clinic letter that says you must call to confirm: must do.
- He puts the power bill and the clinic letter on top, soonest date first.
Jay is a made up example.
Practice: Must, can, should, or just so you know
Sort each made up line.
- You must bring a photo ID.
- You may bring a friend.
- You should arrive 10 minutes early.
- No action is needed.
Check your practice: feedback
- Must. You have to do it.
- Can. It is your choice.
- Should. It is advice, a good idea.
- Just so you know. You do not need to do anything.
Common mistakes
- Treating every letter as an emergency. Sort it first.
- Missing the must in a long letter. Skim for must and due.
- Throwing out just so you know mail. Keep official letters for your records.
Try it: Sort your mail
Pick your scenario:
- I get many bills
- I get letters from agencies
- I get school letters
- Gather this week's mail.
- Mark each as must do, can do, or just so you know.
- Put must do on top, soonest date first.
- Write the next step for the top one.
- File the rest where you can find it.
Do it by: this week
Reflect
Which kind of mail do you get most?
Check your understanding
1. A letter says, You must sign and return this form. What does must tell you?
- You have to do it
- You can choose
- It is only news
See the answer and feedback
A is correct. Yes. Must means it is required.
B: That is may. Review Three kinds of lines.
C: That is for your information. Review Three kinds of lines.
2. A letter says, You may call us with questions. What does may tell you?
- You have to call
- It is up to you
- There is a fee
See the answer and feedback
B is correct. Yes. May means you can choose.
A: That would be must. Review Three kinds of lines.
C: Nothing says fee. Review Three kinds of lines.
3. An IRS letter says it fixed your return. You agree, and it does not ask you to reply. What do you do?
- Reply right away
- Call the IRS to confirm
- Keep it for your records
See the answer and feedback
C is correct. Yes. The IRS says you do not need to reply unless asked.
A: No reply is needed. Review Put must do mail first.
B: The IRS says you do not need to reply if you agree and no reply is asked. Keep it. Review Put must do mail first.
Takeaway: action words
- Must: you have to
- Can or may: your choice
- Should: advice
- No action needed: just so you know
Recap
- Must means you have to.
- May means you can choose.
- For your records means just so you know.
- Handle must do mail first, soonest date on top.
You now have: your mail sorted into three piles.
Next up
Next you will say it in your own words, find free help, and do your capstone. Go to Lesson 5: Say it in your own words.
Sources
- Federal Plain Language Guidelines (March 2011, Rev. 1 May 2011), hosted by IES REL Central (current as of Oct 29, 2026)
- IRS: Understanding your IRS notice or letter (current as of Oct 29, 2026)
