Census - are they dittos or not?

[issi]

Hi, I have this 1891 census and there are marks that have been crossed out against two of the sons. The census transcription doesn't list them as having any occupation, which is odd given their ages. Do people think they might (or might not) have the same occupation as their father (the family business)?
In other places on the page he's used -----do---- and do. for ditto.
There are some other faint notes too. I'll post a fuller view of the page below the relevant image.
Many thanks for any help.
The sons are John H. and Frank:

[rosie99]

What are the names of the people you are querying

[Tickettyboo]

If you mean the large slash marks in the occupation column, they are the enumerators check marks. Each household got an individual form which they completed and the enumerator collected those and transferred the info to the combined document you are looking at.
Once they been transferred they were checked against the individual forms and those marks show which had been checked.

ADDED
There seems to be a faint 'z' in some of the entries, I'd guess it indicates that there was no info for that column/person on the household form

Boo

[issi]

What are the names of the people you are querying

Hi Rosie, John H and Frank in the first image, as I said. Thanks.

[Albufera32]

For the children of Eli Halliwell, there appear to be three sons, the first of whom is john, listed as a cotton weaver with "do" for the next two sons. As mentioned above, the thick black line is a check mark, not  scoring out, so the two younger sons are indeed also cotton weavers.

I think this may be what you are asking about.

You replied while I was posting. I see you meant different people.  As far as I can see the two names you mentioned do indeed have no occupation listed.