3.5.2 HIDDEN

For ELF targeted ports, define a symbol that will be hidden and won’t be exported. The syntax is HIDDEN(symbol = expression).

Here is the example from Simple Assignments, rewritten to use HIDDEN:

HIDDEN(floating_point = 0);
SECTIONS
{
  .text :
    {
      *(.text)
      HIDDEN(_etext = .);
    }
  HIDDEN(_bdata = (. + 3) & ~ 3);
  .data : { *(.data) }
}

In this case none of the three symbols will be visible outside this module.