@DG-Rilling Thank you for your guidance.
Here is how I fixed it.
All changes are made in the ~/htdocs/core/lib/pdf.lib.php
file.
Under the Bank Section:
* Show bank informations for PDF generation
.
.
.
$pdf->SetFont('', '', $default_font_size - 2)
To rearrange the bank fields, I modified this portion:
// Account owner name
$pdf->SetFont('', '', $default_font_size - 2);
$pdf->SetXY($curx, $cury);
$pdf->MultiCell(100, 3, $outputlangs->transnoentities("Account Name").': '.$outputlangs->convToOutputCharset($account->proprio), 0, 'L', 0);
$cury += 4;
// Account Number
$pdf->SetFont('', '', $default_font_size - 2);
$pdf->SetXY($curx, $cury);
$pdf->MultiCell(100, 3, $outputlangs->transnoentities("BankAccountNumber").': '.$outputlangs->convToOutputCharset($account->number), 0, 'L', 0);
$cury += 4;
// Bank Name
$pdf->SetFont('', '', $default_font_size - 2);
$pdf->SetXY($curx, $cury);
$pdf->MultiCell(100, 3, $outputlangs->transnoentities("Bank").': '.$outputlangs->convToOutputCharset($account->bank), 0, 'L', 0);
$cury += 4;
I hope this helps for future reference.
(Note to @eldy) Also, it would be great if this modification and control could be kept on the PDF template and not on system files, so that it would be easier to upgrade without keeping track of system modifications.