What is one to do if he found a lost object that must be returned, and the owner cannot be located?
The general law: Any item that must be returned to its owner [as explained in the laws of Hashavas Aveida], and the owner cannot be traced, is required to be held until the coming of Eliyahu Hanavi, who will than reveal its rightful owner. It is forbidden to make any use of the object, or sell it, until the owner is found. Practically, many of the objects that we find [even without Simanim] in Jewish majority areas must be returned to its rightful owner and fall under the above requirement, due to lack of knowledge if the owner gave up hope of retrieving the item, or had knowledge of its loss, prior to one finding it. This raises the major issue of what one is to do with all the lost objects that he finds, and why do we not see a closet of lost objects being kept in one’s home and eventually inherited from father to son? The following options are recorded in Poskim:
The options recorded in Poskim: Some record that in truth one must store the lost object and guard it for the rest of his life. Others suggest that once one can assume that the rightful owner has passed away, he may then use the object for himself. Other Poskim rule that after all required methods and reasonable timeframe for finding the owner have been exhausted, one may keep the object and do with it as he pleases. This applies both to items with and without Simanim [signs of ownership]. However, he must record the items worth and any possible Simanim in a file. Eventually, if the owner ever shows up, or when Eliyahu reveals the rightful owner, the finder will need to reimburse the owner with payment for the object, based on the assessment of worth that he wrote in his file. Some Poskim however limit this allowance only to objects that do not contain sentimental value and significance, and can be commonly in stores. However, items that have sentimental value, or cannot be regularly purchased in stores, would in truth have to be held until the coming of Eliyahu and cannot be used or sold. Practically, this is the common ruling followed today.
All found objects that are required to be returned to their rightful owner, from the letter of the law must be stored until the coming of Eliyahu. However, the common practice is to rule that it may be kept and used by the finder if the following conditions are fulfilled:
1. The owner cannot be located,
2. The item is commonly available for purchase and is not of sentimental value.
3. One records the value and Simanim of the object in a file.
Example of items that one may keep/use/sell/discard [and mark value in file] if cannot find the owner:
· Common pen or pencil.
· Sefarim that are commonly available for purchase
· Phone [although the information is to be backed up and not erased]
· Sd card [although the information is to be backed up and not erased]
 See Toras Haveida 6 p. 143
 Admur Hilchos Metzia Upikadon Halacha 22 [regarding all lost objects that must be returned] Halacha 2 [regarding object without Siman, which is a dispute and we are Machmir] and Halacha 3 [regarding object with Siman in which all agree] Halacha 8 and 15 [regarding if there is doubt if owner knew of its falling before it was found]; Michaber 267/15; Rambam Gezeila Veaveida 13/10; Mishneh Bava Metzia 29b
 Admur Hilchos Metzia Upikadon Halacha 22; Halacha 2 [regarding object without Siman, which is a dispute and we are Machmir] and Halacha 3 [regarding object with Siman in which all agree]; Rama 260/10
 See Admur ibid Halacha 17; Michaber 259/3
 See Admur Hilchos Metzia Upikadon Halacha Halacha 2 [regarding object without Siman, which is a dispute and we are Machmir] and Halacha 3 [regarding object with Siman in which all agree] Halacha 8 and 15 [regarding if there is doubt if owner knew of its falling before it was found]; Raavad and Tur, brought in Shach 260/26; Shach 260/26 [regarding if has Simanim] and 267/13
 Clear implication of Admur ibid; See Toras Haveida 6 p. 143
 Pischei Choshen 7 footnote 10 based on Nesivos Hamishpat 256 and Chasam Sofer C.M. 122
 Igros Moshe Choshen Mishpat 2/45
 The reason: The Igros Moshe ibid does not mention any reason behind this allowance. Vetzaruch Iyun.
 Toras Haveida ibid; Opinion of Rav Elyashiv; Based on Michaber 267/21 who omitted the wording of the Rambam, as brought in Smeh 267/30 [However Smeh ibid argues; See Chochmas Shlomo 267 ibid]
 Toras Haveida ibid