Hi, when I fill in the clientname for t:button a value (for example xxx), then I see in the HTML indeed the xxx.
When I do that for t:field, I got xxx_field ( so '_field' is attached). Is this the normal behavior?
yes: the reason is that one component sometimes (often) is rendered via more than one contained inner component. Each of the inner components has a clientname which then is dervice from the clientname that you pass to the whole component.