In  transaction MD04 there is a pushbutton "Material notice". As soon as a user adds a material notice, the button label changes: the user's name and the date are displayed on the button, e.g. "Johanssen 20.01.2006".
Is it possible to read the user's name and the date in a script?

Yes, this is possible. You use the  "GetFieldAttribute" command and the technical name of the button:

GetFieldAttribute P[RM61R-MNTXT] text=txt

Now the Variable V[txt] contains the button label, e.g. "Miller 20.01.2006".

If you need the two part user name + date separately, some string handling is necessary, which in GuiXT is always a little bit complicated:

// Put date into V[txtdate]
Set V[txtdate]  "&V[txt]"  search=" "

// Total length of string
Set V[l1] "&V[txt]" -stringlength

// Length of date
Set V[l2] "&V[txtdate]" -stringlength

// Difference =  Length of user name 
Set V[l3]   &V[l1]   -   &V[l2]

// user name
Set V[txtuser] "&V[txt](1-&V[l3])"

// now V[txtuser] and V[txtdate] are the two strings we are looking for.