How to construct this sentence properly? Any competent advise, pleace?

[MarianeM]

Below is a sentence I’ve spotted in a brochure for tourists:

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Discounts apply for groups of 15 or more whole have pre-booked.
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At first glance, it’s pretty clear what is the meaning, however I think something is quite wrong with this sentence as it is.

I have no in-depth knowledge of intricacies of the English and
will be very grateful if someone with such knowledge tell me how the sentence in question should be constructed and spelled properly.

Thanks in advance!

[SoothingDave]

Change "whole" to "who."

[5jj]

Change "whole" to "who."

So simple - but I didn't spot it.

[SoothingDave]

"Please" is spelled with an "s." And you want "advice." "Advise" is a verb. "Advice" is a noun.

[Odessa Dawn]

At first glance, it’s pretty clear what is the meaning, however I think something is quite wrong with this sentence as it is.

Thank you, SoothingDave.

Question: Does the word 'however' over here require commas on both sides?

[SoothingDave]

Thank you, SoothingDave.

Question: Does the word 'however' over here require commas on both sides?

Yes. Or make it two sentences with the second starting with "However,".

"What the meaning is" is more natural, too.