W written on passport

[kofi75]

My sister has a 10year multiple visit visa but has been coming to the UK very frequently so she was questioned at the border this time round for the frequency of her visits.After the office stamped entry but wrote with a pen W under the entry stamp.On top of the stamp he wrote Vipp.
Please can some one explain the meaning of the W written under the entry stamp
We are worried it meant something negative

[AmazonianX]

My sister has a 10year multiple visit visa but has been coming to the UK very frequently so she was questioned at the border this time round for the frequency of her visits.After the office stamped entry but wrote with a pen W under the entry stamp.Did the IO questioned or spoke extensively about the frequency to UK? Can W means Warning??On top of the stamp he wrote Vipp. Visa in previous passport
Please can some one explain the meaning of the W written under the entry stamp
We are worried it meant something negative

Maybe allow some time and request SAR from HO.
How frequent are her visits? Repeatedly on this forum, Visit visa holders are advised on spacing out coming to and stay in UK let's it taken by IO/PoE as living in UK under the guise of being a visitor.

[kofi75]

Thanks for the quick response,yes she was questioned about the frequency of her visots

[razergd1]

Is her visa in the same passport where she got stamped or is it in an expired passport?

[ALKB]

Thanks for the quick response,yes she was questioned about the frequency of her visots

Just how frequent and how long are those visits?

Are you sure it´s a "W" or could it also be a sloppily written "NIV"? If NIV, then it means non-immigrant visa, probably because the visa itself is not in the same passport as the entry stamp.

[Frontier Mole]

The w is a warning about the conditions of her visa. The IO has noted the frequency of her visits and duration of stay.
If it is deemed that she is in breach or the intent is to breach when she arrives in the U.K. next they will curtail her visa at the border.

[AmazonianX]

Is her visa in the same passport where she got stamped or is it in an expired passport?

Most probably previous as that's what vipp refers to; we await OP's confirmation.