If you call this with argument "unused=true" it searches for the translation strings that exist in en_US but are never used.
IMPORTANT: that can take quite a lot of time (up to 10 minutes), you need to tune the max_execution_time on your php.ini accordingly.

Duplicate strings in lang files in /home/modernfactory/public_html/crm/dev/translation/../../htdocs/langs/en_US/ - 86 found

#StringFile and lines
54CurrentValuemain.lang (206 - Current value) (659 - Current Value)
2ByYearaccountancy.lang (165 - By year)
main.lang (753 - By year)
14Browseradmin.lang (965 - Browser)
main.lang (681 - Browser)
29Eventsagenda.lang (12 - Events)
main.lang (851 - Events)
52StatusInterInvoicedinterventions.lang (30 - Billed)
main.lang (472 - )
53NewObjectmain.lang (204 - New %s)
modulebuilder.lang (9 - New object)
55MulticurrencyPaymentAmountmain.lang (345 - Payment amount, original currency)
multicurrency.lang (19 - Payment amount, original currency)
5InternalUseradmin.lang (48 - Internal user)
users.lang (66 - Internal user)
6NewModuleadmin.lang (203 - New)
modulebuilder.lang (8 - New module)
7NoticePeriodadmin.lang (261 - Notice period)
holiday.lang (92 - Notice period)
8LanguageFileadmin.lang (352 - Language file)
modulebuilder.lang (49 - File for language)
9Stringadmin.lang (392 - String)
members.lang (103 - String)
10Intadmin.lang (394 - Integer)
members.lang (105 - Int)
11DateAndTimeadmin.lang (396 - Date and hour)
members.lang (106 - Date and time)
12Fieldadmin.lang (464 - Field)
blockedlog.lang (2 - Field)
exports.lang (60 - Field)
13Upgradeadmin.lang (954 - Upgrade)
install.lang (100 - Upgrade)
15Serveradmin.lang (966 - Server)
install.lang (46 - Server)
16DatabaseServeradmin.lang (968 - Database host)
install.lang (49 - Database server)
17DatabaseNameadmin.lang (969 - Database name)
install.lang (50 - Database name)
18DriverTypeadmin.lang (977 - Driver type)
install.lang (45 - Driver type)
19CompanyNameadmin.lang (998 - Name)
companies.lang (26 - Company name)
20CreditNoteadmin.lang (1206 - Credit note)
bills.lang (280 - Credit note)
21CreditNotesadmin.lang (1207 - Credit notes)
bills.lang (281 - Credit notes)
22WithdrawalsSetupadmin.lang (1466 - Setup of module Direct debit payment orders)
withdrawals.lang (22 - Direct debit payment setup)
23Buyadmin.lang (1550 - Buy)
products.lang (48 - Purchases)
24Selladmin.lang (1551 - Sell)
products.lang (47 - Sales)
25AccountancyCodeadmin.lang (1554 - Accounting Code)
companies.lang (291 - Accounting account)
26CashDeskadmin.lang (1577 - Point of sales)
cashdesk.lang (3 - Point of sale)
27ByDefaultInListadmin.lang (1721 - Show by default on list view)
categories.lang (87 - By default in list)
1LineIdaccountancy.lang (111 - Id line)
exports.lang (41 - Id of line)
3CustomerInvoicePaymentaccountancy.lang (182 - Payment of invoice customer)
banks.lang (98 - Customer payment)
4Natureaccountancy.lang (238 - Nature)
members.lang (160 - Nature)
products.lang (159 - Nature)
28AffectedToagenda.lang (10 - Assigned to)
projects.lang (102 - Allocated to)
30Locationagenda.lang (16 - Location)
stocks.lang (29 - Location)
31InterventionSentByEMailagenda.lang (77 - Intervention %s sent by EMail)
interventions.lang (38 - Intervention %s sent by EMail)
32IBANbanks.lang (31 - IBAN number)
bills.lang (409 - IBAN)
33BICbanks.lang (32 - BIC/SWIFT number)
bills.lang (410 - BIC/SWIFT)
34StandingOrdersbanks.lang (37 - Direct Debit orders)
bills.lang (227 - Direct debit orders)
withdrawals.lang (4 - Direct debit payment orders)
35StandingOrderbanks.lang (38 - Direct debit order)
bills.lang (228 - Direct debit order)
withdrawals.lang (5 - Direct debit payment order)
36Accountbanks.lang (63 - Account)
compta.lang (15 - Account)
37SubscriptionPaymentbanks.lang (100 - Subscription payment)
members.lang (144 - Subscription payment)
38Paymentsbills.lang (63 - Payments)
compta.lang (81 - Payments)
39InvoiceRefbills.lang (304 - Invoice ref.)
compta.lang (197 - Invoice ref.)
40NoSupplierOrderboxes.lang (67 - No recorded supplier order)
orders.lang (78 - No supplier order)
41ShowCompanycashdesk.lang (29 - Show company)
companies.lang (307 - Show third party)
42DeleteFromCatcategories.lang (80 - Remove from tags/category)
compta.lang (238 - Remove from accounting group)
43Customercommercial.lang (4 - Customer)
companies.lang (263 - Customer)
44Prospectcommercial.lang (6 - Prospect)
companies.lang (261 - Prospect)
propal.lang (12 - Prospect)
45ShowTaskcommercial.lang (18 - Show task)
projects.lang (39 - Show task)
46ToPaycompta.lang (64 - To pay)
paybox.lang (14 - Do payment)
47ContractStatusClosedcontracts.lang (9 - Closed)
products.lang (74 - Closed)
48ExportsAreaexports.lang (2 - Exports area)
other.lang (232 - Exports area)
49ExportableDatasexports.lang (6 - Exportable dataset)
other.lang (236 - Exportable data)
50AvailableFormatsexports.lang (27 - Available formats)
other.lang (233 - Available formats)
51CreateUserinstall.lang (56 - Create owner or grant him permission on database)
users.lang (30 - Create user)
56OrderDateorders.lang (10 - Order date)
suppliers.lang (9 - Order date)
57FollowingUrlAreAvailableToMakePaymentspaybox.lang (4 - Following URLs are available to offer a page to a customer to make a payment on Dolibarr objects)
stripe.lang (5 - Following URLs are available to offer a page to a customer to make a payment on Dolibarr objects)
58PaymentFormpaybox.lang (5 - Payment form)
stripe.lang (6 - Payment form)
59WelcomeOnPaymentPagepaybox.lang (6 - Welcome on our online payment service)
stripe.lang (7 - Welcome on our online payment service)
60ThisScreenAllowsYouToPaypaybox.lang (7 - This screen allow you to make an online payment to %s.)
stripe.lang (8 - This screen allow you to make an online payment to %s.)
61ThisIsInformationOnPaymentpaybox.lang (8 - This is information on payment to do)
stripe.lang (9 - This is information on payment to do)
62ToCompletepaybox.lang (9 - To complete)
stripe.lang (10 - To complete)
63YourEMailpaybox.lang (10 - Email to receive payment confirmation)
stripe.lang (11 - Email to receive payment confirmation)
64Creditorpaybox.lang (11 - Creditor)
stripe.lang (13 - Creditor)
65PaymentCodepaybox.lang (12 - Payment code)
stripe.lang (14 - Payment code)
66Continuepaybox.lang (16 - Next)
stripe.lang (17 - Next)
67ToOfferALinkForOnlinePaymentpaybox.lang (17 - URL for %s payment)
stripe.lang (18 - URL for %s payment)
68ToOfferALinkForOnlinePaymentOnOrderpaybox.lang (18 - URL to offer a %s online payment user interface for a customer order)
stripe.lang (19 - URL to offer a %s online payment user interface for a customer order)
69ToOfferALinkForOnlinePaymentOnInvoicepaybox.lang (19 - URL to offer a %s online payment user interface for a customer invoice)
stripe.lang (20 - URL to offer a %s online payment user interface for a customer invoice)
70ToOfferALinkForOnlinePaymentOnContractLinepaybox.lang (20 - URL to offer a %s online payment user interface for a contract line)
stripe.lang (21 - URL to offer a %s online payment user interface for a contract line)
71ToOfferALinkForOnlinePaymentOnFreeAmountpaybox.lang (21 - URL to offer a %s online payment user interface for a free amount)
stripe.lang (22 - URL to offer a %s online payment user interface for a free amount)
72ToOfferALinkForOnlinePaymentOnMemberSubscriptionpaybox.lang (22 - URL to offer a %s online payment user interface for a member subscription)
stripe.lang (23 - URL to offer a %s online payment user interface for a member subscription)
73YouCanAddTagOnUrlpaybox.lang (23 - You can also add url parameter <b>&tag)
stripe.lang (24 - You can also add url parameter <b>&tag)
74YourPaymentHasBeenRecordedpaybox.lang (25 - This page confirms that your payment has been recorded. Thank you.)
stripe.lang (26 - This page confirms that your payment has been recorded. Thank you.)
75YourPaymentHasNotBeenRecordedpaybox.lang (26 - You payment has not been recorded and transaction has been canceled. Thank you.)
stripe.lang (27 - You payment has not been recorded and transaction has been canceled. Thank you.)
76AccountParameterpaybox.lang (27 - Account parameters)
stripe.lang (28 - Account parameters)
77UsageParameterpaybox.lang (28 - Usage parameters)
stripe.lang (29 - Usage parameters)
78InformationToFindParameterspaybox.lang (29 - Help to find your %s account information)
stripe.lang (30 - Help to find your %s account information)
79VendorNamepaybox.lang (31 - Name of vendor)
stripe.lang (32 - Name of vendor)
80CSSUrlForPaymentFormpaybox.lang (32 - CSS style sheet url for payment form)
stripe.lang (33 - CSS style sheet url for payment form)
81Stockproducts.lang (44 - Stock)
stocks.lang (16 - Stock)
82Stocksproducts.lang (45 - Stocks)
stocks.lang (17 - Stocks)
83Movementsproducts.lang (46 - Movements)
stocks.lang (21 - Movements)
84Suppliersproducts.lang (79 - Suppliers)
suppliers.lang (2 - Suppliers)
85ListOfStockMovementsproducts.lang (86 - List of stock movements)
stocks.lang (24 - List of stock movements)
86Unitproducts.lang (161 - Unit)
stocks.lang (36 - Unit)