diff --git a/htdocs/langs/en_US/bills.lang b/htdocs/langs/en_US/bills.lang
index ad1d7f138e5..c0eb886a987 100644
--- a/htdocs/langs/en_US/bills.lang
+++ b/htdocs/langs/en_US/bills.lang
@@ -520,10 +520,10 @@ YouMustCreateStandardInvoiceFirstDesc=You have to create a standard invoice firs
 PDFCrabeDescription=Invoice PDF template Crabe. A complete invoice template (old implementation of Sponge template)
 PDFSpongeDescription=Invoice PDF template Sponge. A complete invoice template
 PDFCrevetteDescription=Invoice PDF template Crevette. A complete invoice template for situation invoices
-TerreNumRefModelDesc1=Return number with format %syymm-nnnn for standard invoices and %syymm-nnnn for credit notes where yy is year, mm is month and nnnn is a sequence with no break and no return to 0
-MarsNumRefModelDesc1=Return number with format %syymm-nnnn for standard invoices, %syymm-nnnn for replacement invoices, %syymm-nnnn for down payment invoices and %syymm-nnnn for credit notes where yy is year, mm is month and nnnn is a sequence with no break and no return to 0
+TerreNumRefModelDesc1=Return number in the format %syymm-nnnn for standard invoices and %syymm-nnnn for credit notes where yy is year, mm is month and nnnn is a sequencial auto-incrementing number with no break and no return to 0
+MarsNumRefModelDesc1=Return number in the format %syymm-nnnn for standard invoices, %syymm-nnnn for replacement invoices, %syymm-nnnn for down payment invoices and %syymm-nnnn for credit notes where yy is year, mm is month and nnnn is a sequencial auto-incrementing number with no break and no return to 0
 TerreNumRefModelError=A bill starting with $syymm already exists and is not compatible with this model of sequence. Remove it or rename it to activate this module.
-CactusNumRefModelDesc1=Return number with format %syymm-nnnn for standard invoices, %syymm-nnnn for credit notes and %syymm-nnnn for down payment invoices where yy is year, mm is month and nnnn is a sequence with no break and no return to 0
+CactusNumRefModelDesc1=Return number in the format %syymm-nnnn for standard invoices, %syymm-nnnn for credit notes and %syymm-nnnn for down payment invoices where yy is year, mm is month and nnnn is a sequencial auto-incrementing number with no break and no return to 0
 EarlyClosingReason=Early closing reason
 EarlyClosingComment=Early closing note
 ##### Types de contacts #####
diff --git a/htdocs/langs/en_US/companies.lang b/htdocs/langs/en_US/companies.lang
index 89463a535b3..b41bb49db13 100644
--- a/htdocs/langs/en_US/companies.lang
+++ b/htdocs/langs/en_US/companies.lang
@@ -449,7 +449,7 @@ CurrentOutstandingBill=Current outstanding bill
 OutstandingBill=Max. for outstanding bill
 OutstandingBillReached=Max. for outstanding bill reached
 OrderMinAmount=Minimum amount for order
-MonkeyNumRefModelDesc=Return a number with the format %syymm-nnnn for the customer code and %syymm-nnnn for the vendor code where yy is year, mm is month and nnnn is a sequence with no break and no return to 0.
+MonkeyNumRefModelDesc=Return a number in the format %syymm-nnnn for the customer code and %syymm-nnnn for the vendor code where yy is year, mm is month and nnnn is a sequencial auto-incrementing number with no break and no return to 0.
 LeopardNumRefModelDesc=The code is free. This code can be modified at any time.
 ManagingDirectors=Manager(s) name (CEO, director, president...)
 MergeOriginThirdparty=Duplicate third party (third party you want to delete)