HP 48g Graphing Calculator - Manual (Page 62)

Current
path
You always have immediate keyboard access to the variables stored
in the current directory. Pressing the fVAl^ key brings up a menu
(the VAR menu) of the last six variables you stored into the current
directory. (Pressing (MD steps you through additional “pages” of
variables.) Since directory names are normally stored in variables,
they also appear in the VAR menu, with bars over the top-left corner
(“tabs”) of their menu labels to show that they are directories.
The HOME directory is the only directory that exists when the
calculator is turned on for the first time. You create other directories
as needed using the Variable Browser.
Where to Store Variables
When you evaluate a variable, the HP 48 searches the current
directory for the name of the variable. If the name isn’t there, the
HP 48 searches up the path until it finds the variable or searches the
HOME directory. Note that it will evaluate the first variable it finds
with the designated name, which may or may not be the one you
had in mind. This suggests several approaches to organizing your
variables:
B Put variables that you want to access from any directory into the
HOME directory.
H Put variables that you don’t want to be able to access from all
directories into a directory not on the current path.
a You can use duplicate variable names, as long as they are not in the
same directory.
5-4 Memory