The phrase "are only suggested" is correct and usable in written English.
It can be used when indicating that something is recommended or proposed but not mandatory.
Example: "The guidelines for the project are only suggested, and you can modify them as needed."
Alternatives: "are merely recommended" or "are just proposed".
Formal boundaries are only suggested, and the music moves in large harmonic clouds and slow arpeggios, melancholic and more than a little mystifying.
The characters aren't begging for money, nor are they providing a service for some predefined remuneration — the tips are only suggested.
"Orange" embraces a pulpier approach, leaning into and then subverting our expectations of a "Caged Heat" melodrama, heightening (and sometimes inventing) tensions that are only suggested in the book.
Unlike Nanak these leaders carry weapons rather than hymnals, which points to reconceived ideals of spiritual and temporal power, though these ideals and how they came about are only suggested here.
During the Middle Ages, there were two harbours west and east of the city's southern square; in the painting they are only suggested by the presence of a mast behind the city.
These associations are only suggested by the findings of this study and they will have to be tested in additional studies with appropriate research designs.
Second, take your parents' advice into consideration but don't let them bully you into fulfilling their dreams — even if they insist they are only "suggesting".
Financial advisers say last week's tax deal doesn't mean they are only suggesting defensive strategies - as it has also created some opportunities for more aggressive investing.
HHS decided to add LGB data collection to the National Health Interview Survey but instead of adding T there, they are only suggesting states add it to the Behavioral Risk Factor Surveillance System surveys, and most states said, "No, thanks".
But the fee was only "suggested," I told them.
