The phrase "add a memo" is correct and usable in written English.
You can use it when instructing someone to include a note or message, often in a business or organizational context.
Example: "Please add a memo to the report to clarify the project's objectives."
Alternatives: "include a note" or "attach a message."
For example, you could pull in music from GarageBand, add a voice memo, or import other audio files saved in a cloud storage site like Dropbox.
Also, a formal decision can be added to a memo; for instance in Fig. 7-3 the decision T-Criterion fulfilled (Raw water) is attached to the memo with the title Toxic.
The memo added, "A replacement pedal should only be offered to a customer after the reinforcement bar has been installed and the customer has expressed dissatisfaction".
Nixon could also "make immense political mileage" by opposing the forced integration of schools "and still be on the side of the angels", Mr Buchanan told his boss in another memo, adding a postscript about the reactions to urban race riots of ordinary, apolitical voters, who after a few drinks showed a "violent anti-Negro, let's buy guns attitude".
These really are working notes, not a manuscript being readied for publication, and Leonardo has no hesitation in adding a personal reminder or practical memo right in the middle of a sheet of mathematical studies.
"We have been out of compliance," the memo said, adding a frowning emoticon.
The memo suggested adding a provision in the law clarifying that it didn't prevent states from asking about a proof of citizenship requirement.
"Our review reaffirms our belief that the vulnerabilities and risks associated with the use of Blackberries in the Mahogany Row [redacted] considerably outweigh the convenience their use can add," the memo said.
